After you create a skeleton, you bind it with the character’s surface so that the surfaces move with the skeleton during animation. Binding is also called skinning, and a character’s surface after binding is called a skin.

It is important that the character’s skin deforms naturally as the skeleton moves. Near joints, the skin bulges or indents when you rotate the joints.

In Maya, the skin deforms because the surface’s vertices (or CVs) move in response to the rotation of adjacent joints. The vertices are known as skin points. This is useful for animating elbows, shoulders, necks, and so on.

By default, the influence a joint has on a skin point’s movement depends on how close it is to that joint. You can edit skin point weighting to change the default movement.

In this lesson you learn how to:

• Bind a skeleton using a smooth bind technique.

• View and modify skin weights using the Paint Skin Weights Tool.

• Use influence objects to enhance the skin deformation of a character.

[2] Open the scene for the lesson

In this lesson, you will load a scene containing a human character and skeleton. Each leg and arm of the skeleton has an IK handle that lets you pose the limbs conveniently. If you completed the prior lesson, the character, skeleton, and IK handles will be familiar.

1. Make sure you’ve done the steps in Preparing for the lessons.

2. Open the scene file named SmoothSkin.mb.

   This file can be found in the GettingStarted2015LessonData\CharSetup directory that you set as your Maya project.

   The character in the scene, Jackie, is displayed in a transparent fashion so you can see the skeleton beneath the surface.

3. Select Window > Settings/Preferences > Preferences. In the Preferences window, click the Kinematics Category. Enter 0.4 for the Joint Size, then click Save.

   This displays smaller joints. At the default size of 1.0, the large joints obstruct your view of the skin.

[3] Smooth binding a skeleton

You use Jackie as the surface to be bound to the skeleton.

To bind the skeleton using smooth skinning

1. Select Jackie.

2. Shift-select the back_root joint.

   The back_root joint is at the base of Jackie’s spine. If you are not sure which joint it is, select it in the Hypergraph (Window > Hypergraph: Hierarchy).

3. Select Skin > Smooth Bind >☐.

4. In the Smooth Bind Options window, set Max Influences to 3, then click Bind Skin.

   A Max Influences value of 3 specifies that three joints influence each skin point. By default, the joint closest to the point has the most influence. The second most influential joint is that joint’s parent or child joint, whichever is closest to the point. The third most influential joint is the nearest parent or child of the second joint. The influence drops with the distance from the joints. The amount of influence each joint has on any skin point is the skin weight.

   The default skin weights create smooth deformations of the skin at elbows, knees, and elsewhere as the nearby joints rotate.

5. Select and move any or all of the four IK handles to pose the arms and legs in various positions in order to get used to posing with the IK handles.

   To select an IK handle, drag a selection box around a wrist or ankle joint. To move a handle, use the Move tool to drag the handle in the desired direction.

   NOTE:

   You can also select the IK handles in the Hypergraph. The handles are indented under jackieSkeleton. Each is named for a leg or arm, for example, ikHandleLeftLeg. For more details on IK handles, see Skeletons and kinematics.

6. If you prefer to turn off the skin’s transparency so you can see the skin more clearly, turn off Shading > X-Ray.

   Do not be concerned that the skeleton pokes through the skin, as the skeleton is not displayed in a rendered image.

   As you pose the arms and legs, examine the skin in the regions where joints bend. For many poses, the skin looks natural. For others, the skin folds, compresses, or bulges unnaturally. The pelvis, shoulders, and torso are common problem areas for various poses. For example, if you move an arm straight up, the shoulder compresses as in the following figure.

   

   There are two ways to improve the smooth skin deformations:

• Add an influence object to eliminate collapsing regions or to create muscle bulge. For example, you can use an influence object to make the shoulder region look more natural in the prior pose.

• Edit skin weights—to remove minor lumps or indented regions. For example, you can fill out an undesirable concave region at the chest that appears when you move the arm to certain poses.

  The following procedures explain the techniques.

[4] Skin weighting and deformations

In the next steps, you’ll learn how joints and skin weights influence deformations at Jackie’s chest. In a subsequent section, you’ll improve uneven deformations.

To see how skin weights affect a skin’s deformation

1. Pose the left arm similar to the following figure. The left breast becomes irregularly shaped.

   

2. Select Jackie.

3. Select Skin > Paint Skin Weights Tool >☐.

4. In the Influences list of the Tool Settings window, select any joint, for instance, pelvis.

   The grayscale color of Jackie’s skin indicates how much influence the selected joint has on the skin deformation. In general, a white region of skin is influenced nearly entirely by the selected joint. A gray region is influenced significantly by one or two additional joints, and a black region indicates skin not influenced by the selected joint at all.

   TIP:

   If you prefer, you can turn on Use Color Ramp in the Gradient section of the Paint Skin Weights Tool to view the influence feedback in color. This can make it easier to see small weights.

   Each point on Jackie’s surface is influenced by three joints, as specified by the Max Influence setting in a prior step. However, one or two of the three joints might have so little influence as to be insignificant.

   In this case, the left breast becoming irregularly shaped as you pose the arm indicates that one or more of the joints is exerting too much or too little influence on the surface. In the next steps, you will determine which joints are influencing the irregular region.

5. Do the following to select the vertices in the problem area:

   • In the Paint Skin Weights Tool, turn on Paint Select mode (below the Influences list).

   • Right-click Jackie’s skin and select Vertex from the marking menu.

   • Paint to select the vertices around Jackie’s shoulder.

6. In the Paint Skin Weights Tool, click the Show Influences

   

   button.

   All joints that influence the selected vertices are selected in the Influences list.

   TIP:

   If you don’t immediately see the selected influences in the list, scroll to find which influences are selected.

   Depending on which vertices you selected, the Influences list shows you that the main joints influencing this region are from the mid and upper back, and the left arm.

7. Now that you have narrowed down which joints are influencing the shoulder, select each entry in the Influences list individually to view the shades of gray on Jackie’s skin.

   The left_arm_root is the main influence. The upper_back, mid_back, and left_top_rib also have influence, though not exactly in the same region.

[5] Modifying skin weights

You can modify the skin weights for any of the influencing joints to alter the irregular region. If you don’t get the desired results when you change the skin weights of one of the influencing joints, you can undo your changes and try another influencing joint.

In general, it’s best to modify the skin weights of the most influential joint first, then work with less influential joints if you don’t get the desired results. Modifying skin weights requires experimentation.

In the next steps, you’ll modify the skin weights for the left_arm_root joint.

To modify skin weights using the Paint Skin Weights Tool

1. Select left_arm_root in the Influences list.

2. Set the Mode to Paint, then set the Paint Operation to Add.

3. Set the Value to 0.1.

4. Drag to paint on the irregular region of the breast.

   As you stroke a region, a red circle icon indicates the area affected by the brush stroke. Each stroke adds 0.1 (10%) to the skin weight. The weight for a skin point has a maximum value of 1 (fully white).

   TIP:

   To change the size of the red circle icon, change the Radius(U) value in the Paint Skin Weights Tool.

   Repeat the strokes several times until the irregular region becomes smoother. The jagged, asymmetrical wireframe at the breast becomes more symmetrical as the skin becomes smoother. The region whitens, which indicates increased influence from the left_arm_root joint. Note that increasing the influence of one joint lessens the influence of the other influencing joints.

5. To check the shape with full-color shading, click the Select Tool

   

   in the Maya Toolbox. (You might also prefer to cancel the selection of Jackie to eliminate the display of the highlighted wireframe.)

   

6. To continue modifying the skin weights, select Jackie and select Skin > Paint Skin Weights Tool, or click

   

   in the Maya Toolbox.

   There are several additional tool settings you might find useful as you modify skin weights:

   • The Smooth paint operation smooths the weights of points by averaging the stroked points with the weights of the surrounding region. This is useful if you add to the weight values in some region but the points become unevenly weighted. Uneven weights are indicated by mottled gray skin.

   • The Weight Hammer button

     

     lets you select vertices in a region with undesirable deformation then click to quickly flatten the area. This tool checks the weight values of neighboring vertices and applies the same weight value to the selected vertices.

   • You can use the Scale operation with a Value less than 1 to scale down the point weights of a stroked region.

   • You can select any of the Profile icons to specify the region affected by strokes. The two leftmost icons are the most commonly used shapes.

7. After you eliminate the irregular region from the left breast, move the arm to different positions to see if the breast’s shape stays natural in various poses.

   It is common for a surface to look good in one pose but not in another. Strive to make the surface look good in the poses that you are likely to use during animation.

8. If you want more practice, pose the right arm as you posed the left arm and fix the corresponding irregular region in the right breast. This time, fix the region by modifying the weights for the upper_back joint rather than the right_arm_root. As mentioned previously, you can modify point weights of alternative joints to get a similar effect.

[6] Influence objects

You can create an object and use it to influence the shape of smooth skin. The object, called an influence object, acts like a surgical implant against which the skin deforms. For example, you can create a sphere and use it to simulate a muscle or bone that bulges as you pose the character in certain positions. You can also use an influence object to smooth deformation and maintain volume in regions that collapse while bending.

In the next steps, you’ll use a sphere as an influence object to simulate an elbow jutting out as Jackie’s arm bends. To use an influence object, the skeleton must be in the bind pose—the original pose at which the skin was bound to Jackie.

To return the skeleton to the bind pose

1. Click the Select Tool and cancel the selection of Jackie.

2. Turn off Modify > Evaluate Nodes > IK Solvers.

   After you use an IK handle to pose a character, you must do this step before you can return the skeleton to the bind (T-stance) pose.

3. Select back_root, the root of the skeleton.

   

4. Select Skin > Go To Bind Pose.

5. Select the ikHandleLeftArm in the Hypergraph. Use the Move Tool to move the handle manipulator slightly in any direction. When you release the mouse, note that the arm does not move and that the IK handle manipulator snaps back to the desired position at the end of the joint chain. Repeat this step for any other IK handles you posed previously.

6. Turn on Modify > Evaluate Nodes > IK Solvers.

   You must do this step to enable the IK solvers so you can manipulate IK handles in the scene again.

To position a sphere to be used as an influence object

1. Shift-click Jackie’s surface (anywhere but on the skeleton) and select Actions > Template from the marking menu.

   By making Jackie a template, you won’t accidentally select Jackie in subsequent steps.

2. Create a sphere (select Create > Polygon Primitives > Sphere) and name it elbow_influence.

3. Scale the sphere to be slightly smaller than any of Jackie’s joints (see illustration below).

4. Move the sphere so that its surface is positioned where the elbow would jut out, but still within the skin. You can optionally reshape the sphere’s curvature to resemble the tip of an elbow jutting out from a bent arm. For example, you can scale the sphere in one dimension to squash its shape or you can move individual vertices. A top view of the sphere’s shape and position follows:

   

   The exact position and scale of the sphere is unimportant. You can make slight position and scale adjustments later to enhance the deformations that result from its use.

To make the sphere an influence object

1. In the Hypergraph, select Jackie and Shift-select elbow_influence.

2. Select Skin > Add Influence >□. In the Add Influence Options, select Edit > Reset Settings, and then click the Add button.

   Maya completes the operation within a few moments. To ensure the influence object stays in the correct position at the elbow, you will parent it to the left_shoulder joint.

3. In the Hypergraph, Shift-select elbow_influence, elbow_influenceBase, and left_shoulder joint, in that order.

   The order of selection is important. The parent object should be selected last.

4. Press p to parent the elbow nodes under the left_shoulder joint.

   The elbow_influence nodes appear in the skeleton hierarchy below the left_shoulder joint.

   The elbow_influenceBase is known as a base object. It stores vertex position information for the influence object. The reason for parenting the base object to the left_shoulder joint is so that the influence object’s vertices stay in the correct position at the elbow whenever the elbow moves to a new position. Other than this step, you do not work with the base object.

5. Right-click Jackie and select Actions > Untemplate. It is easier to see subsequent skin deformations when Jackie is displayed with smooth shading rather than as a template.

6. From the menus at the top of the top view, turn off Show > Joints to avoid having the joints obstruct your view of the skin.

7. Use each arm’s IK handle (ikHandleLeftArm and ikHandleRightArm) to pose the arms in the following position.

   

   The left elbow looks more natural than the right elbow. To tune the elbow’s deformation during bending, change the position, scale, and rotation of elbow_influence.

   Do not be concerned if the influence object pokes through the skin. It won’t be displayed when you render the animation.

[7] Beyond the lesson

In this lesson you learned how to:

• Bind a skeleton to a single surface.

  You can bind a skeleton to multiple surfaces or even to a selection of polygonal vertices or NURBS CVs or subdivision surfaces.

• Use the Paint Skin Weights Tool to prevent a region from collapsing upon deformation.

  To control skin weights with more precision than shown in the lesson, you can modify skin weights numerically with the Component Editor. If you smooth skin multiple surfaces which have been seamed together, there are many tool settings for the Paint Skin Weights Tool that make the task easier.

• Use an influence object to make an elbow stick out upon bending.

  Another common use of an influence object is to simulate a muscle bulging during joint rotation. The technique requires use of Set Driven Key to link the bulging influence object’s scale values to the rotation of the appropriate joint. A brief example of this technique is provided in the Maya Help for Smooth Skin.

Skin weights and influence objects cannot overcome all modeling problems. For instance, if you further separate Jackie’s legs sideways, you will see an undesirable fold at the hips. This occurs because of the asymmetrical arrangement of polygonal edges in the hip region of the original model. To fix the problem, you would need to detach the skin, alter the original model, then smooth bind the model again.

Maya has an alternative skinning method, rigid skinning, which gives results similar to smooth skinning but requires use of different enhancement tools: flexor and lattice deformers. In general, smooth skinning gives more natural deformations with less effort than rigid skinning. If you skin multiple seamed surfaces, however, processing is faster with rigid skinning than with smooth skinning.

Smooth skinning is just one of the techniques for perfecting a character’s deformations during animation. You can use Maya’s other deformers alone or in addition to smooth skinning to achieve the results you want.

After you model the surfaces that make up a human, animal, or other character, you create a skeleton and bind it to the character’s surface (called skin).

A skeleton provides a structure for animating the character. When you create a skeleton in Maya, you create a series of bones with joints in the skeletal locations where you want the character to bend or twist. (You can animate a skeleton without having a skinned character.)

In this lesson, you learn the techniques for creating a simple skeleton for a human character. You will learn how to:

• Create joints for a character.

• Name joints in the Hypergraph.

• Use symmetry when creating a character.

• Parent joints into an existing skeleton.

• Use Inverse Kinematics (IK) techniques to pose a skeleton.

Learning how to bind a character to a skeleton is described in the next lesson.

[2] Open the scene for the lesson

In this lesson, you’ll load a scene that contains a human character. During the lesson, you’ll create and animate a skeleton for the character.

To open the scene

1. Make sure you’ve done the steps in Preparing for the lessons.

2. Open the scene file named Skeleton.mb.

   This file can be found in the GettingStarted2015LessonData\CharSetup directory that you set as your Maya project.

   The character displayed in the scene, Jackie, is a template, so you cannot unintentionally select it during the lesson. Jackie was modeled in the Da Vinci pose, the position that’s easiest for creating a skeleton.

[3] Creating joints

A skeleton is made of bones and joints. When you create a skeleton in Maya, you create a series of joints in the skeletal locations where you want the character to bend or twist.

A common technique for creating a skeleton is to create several independent joint chains—one for each arm, one for each leg, one for the spine/head—then group the chains together to create a single skeletal hierarchy. In the steps that follow, you create the joints for the legs.

To create joints for the legs

1. Select Window > Settings/Preferences > Preferences. In the Preferences window, click the Kinematics Category. Enter 0.4 for the Joint size, then click the Save button.

   This displays the joints smaller when you create them in the next steps. At the default size, 1.0, the size of the joints makes them hard to position accurately for this character.

   NOTE:

   The default joint size of 1.0 has been used to create the joints pictured in the following illustrations. The joints you create may appear smaller than those pictured in this lesson.

2. Select Skeleton > Joint Tool. This is the tool for creating the joint chains that make up a skeleton.

3. In a side view, click at the hip, knee, ankle, ball of foot, and toe to create joints at these positions (see the following figure). Make sure the knee joint is in a position that creates a slight forward bend. The forward bend ensures that you will be able to animate the leg easily in a direction natural for a leg.

   

   TIP:

   Press Alt +b (Windows) or Option +b (Mac OS X) to toggle between default background colors in the scene view.

4. Press Enter (Windows and Linux) or Return (Mac OS X) after creating the toe joint. This completes the joint chain.

5. Select Window > Hypergraph: Hierarchy.

   The Hypergraph is a convenient place to select, rename, and parent objects. It is similar to the Outliner, but it has features tailored for character setup. For example, it depicts all parent-child relationships in an easy-to-read indented format.

   The Hypergraph shows the default names given to the joints just created: joint1, joint2, and so on. The joints have a hierarchical relationship. Joint1 is the parent of joint2, which is the parent of joint3, and so on. Joint1 is the root of the hierarchy. If you reposition joint1, you reposition the whole joint chain.

   In the scene view, joints are represented by spherical icons. Bones separate the joints, and are represented by elongated pyramid icons. The narrow part of a bone points in the downward direction of the hierarchy.

   The reason you create the hip joint first and the toe joint last is to have the hip at the top of the hierarchy and the toe at the bottom. You’ll usually want the toe (and other joints) to move whenever you move the hip, but not necessarily vice versa. In general, joint chains emanate from the interior of the character outward.

6. Rename the joints as left_hip, left_knee, left_ankle, left_ball, and left_toe. To rename a joint, right-click the joint name in the Hypergraph and select Rename from the drop-down menu. Type the new name and press Enter.

7. In the front view, click the left_hip joint to select it. Move it along the X-axis to the center of the top of the left leg. (In this lesson, left and right refer to directions from Jackie’s point of view, not from your view of the scene.)

   As mentioned before, when you move a joint, all joints lower in the hierarchy move with it. If you press Insert (Windows and Linux) or Home (Mac OS X) while a joint is selected, you can move the joint without moving joints below it in the hierarchy. (To exit this mode, press Insert or Home again.)

8. Rotate left_hip so that the skeleton fits inside the leg. It’s unnecessary to fit the skeleton perfectly inside the character, as it won’t be displayed when you render an image from the scene.

   

9. To create the joints for the other leg, you can save time and ensure symmetry by duplicating the existing leg joint chain with mirroring. With left_hip selected, select Skeleton > Mirror Joint >☐. In the options window, turn on YZ for Mirror Across.

   Jackie’s legs straddle the YZ plane, so mirroring the joint chain across the YZ plane positions the duplicate joint chain in the desired location. This operation illustrates that Jackie’s original position affects the ease with which you can create the skeleton. Had Jackie been positioned away from the origin, you would not have been able to use Mirror Joint to duplicate the leg’s joint chain.

10. Enter left in the Search for field and enter right in the Replace with field.

    The Replacement names for duplicated joints feature automatically replaces the names of all duplicate joints with the specified joint prefix.

11. Click Mirror.

    The right leg bones and joints appear in a mirrored position.

    

In the next steps, you create a joint chain for the spinal column. You also extend a joint from the upper neck region of the joint chain so that you can animate the jaw.

To create joints for the spine and jaw

1. In the side view, use the Joint Tool (Skeleton > Joint Tool) as follows to create a series of joints at the locations shown in the following figure:

   

   • Start at the base of the spine near the existing hip joints (left_hip and right_hip) and end at the top of the head.

   • Make sure you create the first joint a little bit away from the existing hip joint displayed in the front view, otherwise the first joint will be connected to the hip joint.

   • Press Enter (Windows and Linux) or Return (Mac OS X) when you are finished creating the joint chain.

With the exception of the joints at each end of the joint chain, the joints are located where the character is likely to bend or twist at the spine and neck.

The S-shaped curvature of the joint chain resembles Jackie’s spinal curvature. This makes it easier to animate the character’s torso and neck naturally.

2. Open the Hypergraph and, starting at the base of the spine, name the joints back_root, pelvis, lower_back, mid_back, upper_back, lower_neck, upper_neck, and crown.

3. To set up the skeleton for jaw movement, extend a joint from the upper_neck joint as follows:

   • Select the Joint Tool, and click the upper_neck joint in the Hypergraph to select it.

   • In the scene view, click to create a new joint near the lips, and press Enter or Return.

   • Name the new joint as jaw.

Creating joints for the arms is similar to creating joints for the legs.

To create joints for the arms

1. In the front view, create a series of joints at the locations shown in the following figure. Start at the pectoral region (near the upper_back joint) and end at the wrist.

   

2. Name the joints left_arm_root, left_shoulder, left_elbow, and left_wrist.

3. In the top view, select the left_elbow joint, select the Move tool, press Insert (Windows and Linux) or Home (Mac OS X), then move the joint to the back of the arm. Press Insert or Home again.

   

   Moving the joint to the back of the arm creates a bend at the elbow. This will make it easier to animate the character’s arm in the direction an arm naturally bends.

   

4. In the perspective view, select left_arm_root. Select Skeleton > Mirror Joint. This creates a copy of the left arm’s joint chain for the right arm and renames them in the process.

   The right arm bones and joints appear in a mirrored position.

   

[4] Adding joints to a skeleton

When you bind a character to a skeleton (described in the next lesson), the skeleton provides a structure for the character’s skin and prevents the skin from collapsing as you pose the skeleton.

It’s useful to add extra joints in areas of the character where you want the surface to keep its volume upon deformation. In the next steps, you’ll add ribs to Jackie’s skeleton. Although you will not bind the character in this lesson, the technique of adding ribs is important to learn so that when you do bind a character, the skin in the torso area will not collapse as you pose shoulder and spinal rotations. The rib joints are for structure only, not for posing the skeleton.

To add ribs to the skeleton

1. In the Hypergraph, click the mid_back joint to highlight the joint in the front view. Remember the location of the joint in the front view so you can select it later.

2. Select Skeleton > Joint Tool.

3. In the front view, click on the mid_back joint to select it again.

4. Click to the side of the joint to add a rib bone, then press Enter (Windows and Linux) or Return (Mac OS X).

   

5. With the same technique as in the prior steps, create two more ribs for the left side. The ribs extend from the mid_back, lower_back, and pelvis joints.

   

6. For easy identification in the Hypergraph, you can optionally name the ribs as desired. For instance, name them left_top_rib, left_mid_rib, left_bottom_rib, and so on.

7. Mirror each of the left rib joints to create ribs for the right side of the skeleton.

[5] Creating a skeleton hierarchy

So far you have created five separate joint chains: one for the spine, and one for each arm and each leg. You need to create a single hierarchy from the five joint chains so you can move all of them as a single unit. To create the single hierarchy, you parent the arms and legs to the nearest joint in the spine.

To parent the arm and leg joint chains to the spine

1. In the Hypergraph,MiddleClick-drag left_arm_root to upper_back.

   When you parent one joint to another, Maya creates a bone that connects the parent to the child. In this case, the bone connects upper_back to left_arm_root.

2. MiddleClick-drag right_arm_root to upper_back.

3. MiddleClick-drag left_hip to back_root.

4. MiddleClick-drag right_hip to back_root.

   Now if you need to move the entire skeleton, you can move back_root—the root of the hierarchy. The completed skeleton is shown in the following figure (with Jackie hidden).

   

[6] Forward and inverse kinematics

There are two techniques for posing a skeleton: forward kinematics and inverse kinematics.

Forward kinematics (FK)

To pose a character with forward kinematics, you rotate each joint individually until you get the desired positioning. For example, to move a hand to some location, you must rotate several arm joints to reach the location.

When you animate a skeleton posed with forward kinematics, Maya interpolates the joint rotations starting with the root joint, then the root’s child joints, and so on down through the skeleton’s action hierarchy. Maya proceeds forward through the action hierarchy, starting at the root joint.

Forward kinematics is intuitive for creating simple arc motions, but it’s tedious if you are animating a complex skeleton. It’s also not intuitive for specifying goal-directed motion. For example, to move a hand to some location, it’s not obvious how to rotate the joints in an arm.

Inverse kinematics (IK)

With IK, you create an extra control structure, an IK handle, for certain joint chains such as arms and legs. An IK handle lets you pose and animate an entire joint chain by moving a single manipulator.

As you pose the IK handle, it automatically rotates all the joints in the joint chain. For example, if you move a hand to a doorknob, the other joints in the arm rotate to accommodate the hand’s new positioning.

IK is more intuitive than forward kinematics for goal-directed motion because you can focus on the goal rather than on how you need to rotate each joint to achieve that goal.

[7] Posing and animating using inverse kinematics

Next, you create IK handles that you’ll later use to pose the arms and legs. The next steps describe some initial setup you should perform before creating the IK handles.

To set up the character prior to creating IK handles

1. Select the root of the hierarchy, back_root, and then select Skeleton > Set Preferred Angle.

   This sets the current joint angles throughout the skeleton as the preferred angles. This is a useful step after you complete a skeleton. Maya thereafter uses the current bend in the knees and elbows as the preferred initial rotation direction of these joints during inverse kinematics (IK) posing. This makes it easier to pose the character with motion that is natural for a human character.

2. Select Jackie in the Outliner (Window > Outliner) and, from the main menu, select Display > Hide > Hide Selection. (You must select Jackie from the Outliner because Jackie is a template object.) By hiding Jackie, you’ll lessen scene clutter as you pose the skeleton in the following steps.

To create, pose, and animate IK handles for the legs

1. Select Skeleton > IK Handle Tool >☐.

2. In the Tool Settings window, make sure Current Solver is set to Rotate-Plane Solver.

   This type of IK solver has characteristics that work well for this application.

3. In the perspective view, click left_hip and left_ankle.

   This creates an IK handle that lets you control all joints from left_hip through left_ankle. The handle’s main manipulator is at the left_ankle.

   The IK handle is the selected object after you create it. If you unintentionally cancel the selection of the handle, you can select it again by clicking the left_ankle—the last joint you clicked after using the IK Handle Tool. Whenever you select a handle, make sure you do not select joints or other objects along with the handle. You can check the Outliner to confirm your selection.

4. Go to the start of the playback range.

5. With the IK handle selected, select Animate > Set Key to key the leg’s current position at the first frame.

6. Go to frame 12.

7. In the side view, use the Move tool to drag the IK handle up and to the left (see following image), as if Jackie were stepping up a staircase. The foot and knee move while the hip stays in place.

   

8. Set another key for the IK handle.

9. Go to frame 24. Move the IK handle back to its prior position. Set another key.

10. Play the animation to see the leg step up and down during the first 24 frames.

    This completes a simple animation of the leg using an IK handle to control its position.

To practice additional IK techniques

1. Go to the start of the animation.

2. In a perspective view, practice posing the leg in various directions by moving the IK handle.

   No matter how far you drag the handle manipulator, the joints of the leg will not stretch beyond the straight leg position. This is desirable; you do not want the size of a skeleton to change as you pose it. However, if you drag a leg joint, the bone hierarchically above that joint will lengthen. This is why it’s important to check that you haven’t selected a joint with the IK handle before you move the handle.

   As you drag the handle to some positions, you might notice the leg joints flip abruptly (see the next image for an example position). It’s therefore hard to control the leg positioning in this region.

   The default IK handle (IK Rotate Plane handle) has manipulators you can use to avoid joint flipping. With the handle selected, select Modify > Transformation Tools > Show Manipulator Tool. Move the Pole Vector XYZ manipulator to a slightly different position (see the following image).

   If this doesn’t solve the problem, rotate the Twist manipulator to rotate the leg. You can key the Pole Vector XYZ and Twist attributes to fixed values to avoid the flipping as the character moves.

   A more precise way to avoid joint flipping, which requires some initial setup, is to use a Pole Vector Constraint.

   

3. Repeat the preceding steps for the right leg. (Create an IK handle for the right_hip to right_ankle, then practice posing and animating the handle.)NOTE:

   If you want to move the entire skeleton, group the back_root and all IK handles under a single node, select the group node, and then use the Move tool. With this grouping, the motion of the entire skeleton won’t conflict with the keys you set for the handles.

To create, pose, and animate IK handles for the arms

1. Select Skeleton > IK Handle Tool.

2. Click left_shoulder, and then click left_wrist. This creates an IK handle for the left arm.

3. Select Skeleton > IK Handle Tool.

4. Click right_shoulder, then click right_wrist. This creates an IK handle for the right arm.

5. Practice posing and animating the handles.

[8] Posing and animating using forward kinematics

As the last part of the lesson, you can optionally practice posing and animating the character by rotating joints that are not controlled by IK handles—the ball joints of the feet, and joints from the back_root through the upper_neck. Rotating such joints is forward kinematics.

With the exception of the back_root, you’ll invariably rotate rather than move the joints that aren’t part of an IK handle. If you move the joints, the bones lengthen. This deforms bound skin undesirably unless you are creating cartoon-like distortions.

Because you’ve already set keys for IK handles, some joint rotations on non-IK handle joints will be restrained by the IK handle positioning. If this interferes with the intended poses, you can remove all prior animation from an IK handle by selecting Edit > Keys > Delete Keys. You can also use Delete Keys to remove all animation from keys you’ve set with forward kinematics.

[9] Beyond the lesson

In this lesson you learned how to:

• Create a skeleton with bones and joints.

• Pose the skeleton using Inverse Kinematics.

Additional things to consider when working with skeletons:

• The appropriate number of joints in a skeleton depends on the anatomical parts of the character you want to manipulate. More joints means finer control at the expense of greater complexity.

• As you created the skeleton in this lesson, you ended the arm’s joint chain at the wrist. This prevents you from animating hand motion. If you need to animate hand motion or even finger motion, you would need to make additional joints and IK handles. The same applies to foot and toe motion.

• When you create a skeleton, you can animate a character bound to it to produce natural skin deformations. Although you animated an unskinned skeleton in this lesson, it’s more common to animate a skinned skeleton. Binding a character is the topic of the next lesson.

• It’s typically best to animate the entire skeleton from pose to pose at desired frames. It’s hard to get desired results by animating one limb for a frame range, another limb for a frame range, and so on.

There are many other ways to work with skeletons not described in this lesson:

• You can blend or switch between IK and forward kinematics on joints controlled by an IK handle.

• There are other types of IK handles that provide different controls for manipulating parts of a skeleton. Especially noteworthy is the IK spline handle, which makes it easy to animate the twisting, wavy motion in tails, necks, spines, snakes, and so on.

For more details on these and other features, please refer to the Maya Help.

Path animation allows you to animate an object along a path specified by a curve. In this way, the curve controls the motion of the object. With keyframe animation, Maya calculates the motion of the object for the animation based on the positions that were set at the keyframes. With path animation the motion for the object is defined by its location along the path curve.

Path animation is useful for animating objects such as trains, boats, airplanes, and moving cameras whose motion follows a set path. To animate an object to do this type of motion smoothly with keyframe animation would require you to laboriously create and edit many keys for the motion. By having the object move along a curve, you can easily adjust the object’s path by editing the curve.

In this lesson, you make an aircraft follow a motion path so it appears to fly and bank while it changes trajectory.

In this lesson, you learn how to:

• Set an object to animate along a motion path using a NURBS curve as the path.

• Modify the timing and rotation of an object along a motion path.

• Blend between keyframe and motion path animation.

[2] Open the scene for the lesson

In this lesson, you work with a scene we created for your use.

1. Make sure you’ve done the steps in Preparing for the lessons.

2. Open the scene file named PathAnim.mb.

   This file can be found in the GettingStarted2015LessonData directory that you set as your Maya project.

   

   The scene contains two objects named Aircraft and PathCurve. When the aircraft travels on the path curve it will return to where it began.

3. In the Time Slider, ensure that the Playback End Time is set to 240.

   

The path animation occurs between frames 60 and 240 (180 frames in total). Between frames 1 and 60, you keyframe the aircraft’s motion so it rises from the ground plane. You then blend between the two animation types.

[3] Animating an object along a motion path

To animate the aircraft along the path curve, first select the aircraft and the path curve and then set appropriate options for the motion path animation. In the options window, you need to set the required time range for the path animation. You also need to ensure that the aircraft is oriented facing towards the direction of travel. The Follow, Front, and Up axis option settings determine the aircraft’s orientation along the path.

To attach the aircraft to the motion path

1. Go to frame 1 on the Time Slider.

2. Select the aircraft and then Shift-select the path curve.

3. In the main menu, select Animate > Motion Paths > Attach to Motion Path >☐.

   The Attach to Motion Path Options window appears.

4. In the options window, ensure the options are set as follows, then click Attach:

   • Time Range: Start/End

   • Start time: 60

   • End time: 240

   • Follow: On

   • Front Axis: X

   • Up Axis: Y

   • World up type: Scene up

   • Leave all other settings off

     

5. Click Attach.

   The aircraft is repositioned to the start of the curve, and oriented towards the direction of travel.

   

   The Start and End times set the time duration the aircraft travels along the path curve (240 - 60 = 180 frames). The start and end times are displayed at the ends of the curve.

6. Click play on the Time Slider playback controls to play back the animation.

   The aircraft travels along the path. Observe that it begins its motion at frame 60.

   

[4] Changing the timing of an object along a motion path

When you first assign an object to a motion path, by default, the object travels along the path at a constant speed. In this lesson, you want the aircraft to initially travel along the path slowly, accelerate, and then finally move more slowly when it nears the end of the motion path.

You can change the rate of travel for the aircraft by keyframing attributes that affect where the aircraft is positioned on the curve at a given time.

To view the attributes for the motion path

1. Go to frame 1 on the Time Slider.

2. Select the aircraft.

3. Open the Channel Box by clicking the Show/Hide Channel Box icon on the Status Line.

   

4. In the Channel Box, click on the word motionPath1 that appears in the Aircraft’s Inputs list.

   The attributes for motionPath1 appear at the bottom of the Inputs list. (Scroll the Channel Box window if the motionPath1 attributes are not fully visible).

   

The U Value attribute controls where the aircraft gets positioned along the curve. The U Value refers to the curves parameterization. Parameterization is a method used by Maya to divide a curve into increments of known amounts so that a location along the curve can be determined.

By default, the parameterization of a path curve is set between zero and one. At frame 60, the aircraft is at the beginning of the curve where the parameterization value is zero. When the aircraft is at the end of the curve (frame 240) the parameterization value for the curve is one. When the aircraft is halfway through the path animation (frame 150), it is located along the curve at a U Value of 0.5.

By setting the frame number and U Value and then setting a key, you change the timing for the aircraft’s motion along the path.

To change the timing for the aircraft along the path

1. Ensure the aircraft is selected so its attributes display in the Channel Box.

2. In the Time Slider, drag the current time indicator to frame 120 using the middle mouse button.

   Middle-dragging the current time indicator, instead of using the left mouse button, changes the current time without repositioning the aircraft along the path.

   

3. In the Channel Box, set the U Value for motionPath1 to 0.1.

   The aircraft is repositioned along the curve near the first bend. When you set the U Value to 0.1, the aircraft is positioned at a point that is a distance of 10 percent from the beginning of the curve (that is, the aircraft has completed 10 percent of the distance along the path).

4. Select the U Value channel, then right-click the name and select Key Selected from the drop-down list.

   

   A position marker appears on the path curve indicating that a key frame has been set. The position marker is useful for determining where the aircraft is at a given time. Position markers do not appear when you render the animation. Using Key Selected ensures that a keyframe is set only for the item selected and nothing else.

   

5. In the Time Slider, middle-drag the current time indicator to frame 180.

6. In the Channel Box, set the U Value for MotionPath1 to 0.9.

   The aircraft is repositioned along the curve near the last bend. When you set the U Value to 0.9, the aircraft is positioned at a point that is a distance of 90 percent from the beginning of the curve. (that is, the aircraft has completed 90 percent of the distance along the path)

7. Select the U Value channel, then right-click and select Key Selected from the drop-down list.

   A position marker appears on the path curve.

   

8. Click play on the playback controls to play back the animation.

   The motion of the aircraft is not smooth as it travels along the path. It initially moves forwards and backwards a bit at the beginning and end of the path. This indicates that some adjustment of the animation is required. You adjust the animation using the Graph Editor.

To view the Graph Editor

1. From the main menu, select Window > Animation Editors > Graph Editor.

   The Graph Editor appears.

2. In the Graph Editor, select View > Frame > Frame All.

   The Graph Editor updates to display the animation curve for the motion path animation.

   

The shape of the animation curve provides some clues as to why the motion of the aircraft is not smooth. Between frames 60 and 84 the curve rises and then drops slightly. Because the animation curve represents translation along the curve, a drop in the curve indicates that the object travels backwards. A similar occurrence happens at the end of the curve as well. To correct this, you need to modify the tangents for the keys in the Graph Editor.

To edit the tangents for the keys in the Graph Editor

1. In the Graph Editor, press the shift key, then double click on the animation curve to select the four keys (frames 60, 120, 180 & 240)

2. In the Graph Editor menu, select Tangents > Linear.

   The animation curve updates so that the keys connect via straight lines. This eliminates the dips in the curve that caused the aircraft to travel backwards.

   

Next, you modify the tangents for keys 120 and 180 so the aircraft accelerates and decelerates near those points on the path curve.

1. In the Graph Editor, shift-select only the two keys for frames 120 and 180.

2. In the Graph Editor menu, select Tangents > Break Tangents.

   Breaking the tangent for the keys allows you to modify the shape of the curve as it enters or leaves a key.

3. Select only the key for frame 120.

   A pair of tangent handles appear on either side of the key. The handles let you edit the curvature of the animation curve near the key point.

4. Select the tangent handle to the right of the key.

   The handle highlights in a yellow color.

5. From the Toolbox, select the Move tool.

6. Using the middle mouse button, drag the handle so the curve has a gentle curvature as it leaves the key as shown below.

   Modifying the tangent in this manner changes how the motion transitions as the curve changes direction as it passes through the key. The aircraft will accelerate smoothly instead of immediately travelling at a different rate of speed.

   

7. Select the key for frame 180.

8. Select the handle to the left of the key.

   The handle highlights in blue.

9. Using the middle mouse button, drag the handle so the curve has a gentle curvature as it enters the key as shown below.

   Modifying this tangent for this key will cause the aircraft to decelerate smoothly near the end of its travel.

   

   The modified animation curve appears as shown below.

   

10. Close the Graph Editor.

11. Click play on the Time Slider’s playback controls to play back the animation.

    The backwards and forwards motion that previously occurred is corrected. The aircraft travels slowly towards the first bend in the path curve, then accelerates and travels at a constant speed around the curve until it nears the end of the path where it decelerates and then slowly moves towards the end of the curve.

[5] Rotating an object along a motion path

As the aircraft travels along the motion path, its orientation remains the same throughout the animation. A real aircraft rolls to one side (banks) as it flies in an arc. To make the aircraft roll to one side as it travels along the path you set keyframes for the Twist attributes in the Channel Box.

To animate the roll of the aircraft along the path

1. Ensure the aircraft is selected.

2. Set the Time Slider to frame 120.

   The aircraft is repositioned along the curve near the first bend.

3. In the Inputs section of the Channel Box, click on motionPath1 to view its attributes.

4. Ensure the Front Twist value for motionPath1 is set to 0.

5. Select the Front Twist channel, then right-click and select Key Selected.

   

6. To set the remaining keyframes for the rotation of the aircraft, use the table below as a guide, keeping in mind that you set the keyframes in the following order:

   • Set the frame in the Time Slider

   • Set the values for Front Twist in the Channel Box.

   • Select the Front Twist channel by clicking its name, then right-click and select Key Selected.

     

7. Click play on the Time Slider playback controls to play back the animation.

   The aircraft rolls to one side (banks) as it travels along the motion path.

   

[6] Blending keyframe and motion path animation

Blending between motion path and keyframe animation types is possible in Maya. Blending between the two animation types allows you to take advantage of the characteristics each animation type can provide without having to expend a lot of effort in determining where the change between the two types must occur.

In the steps that follow, you keyframe the aircraft to rise vertically from the floor surface and then travel along the motion path by blending between the two animation types. To accomplish this, you do the following:

• Move the motion path up above the ground plane.

• Keyframe the aircraft so it rises vertically above the ground plane.

• Blend between the keyframe and motion path animations.

To move the motion path

1. In the scene view, select only the path curve.

2. In the Channel Box, set Translate Y to 5 for PathCurve.

   The path curve is repositioned above the ground plane in the scene view. The aircraft moves with the path curve because it is attached to the motion path.

   

To keyframe the motion for the aircraft

1. Select only the aircraft.

2. Set the Time Slider to frame 1.

3. In the Channel Box, set Translate Y to 0.

   The aircraft is repositioned so it rests on the ground plane.

4. Select the Translate X, Y, and Z channels as well as the Rotate X, Y, and Z channels by click-dragging on their names so they become highlighted.

   

5. Right-click on any of the highlighted names, and choose Key Selected from the drop down list that appears.

   Keys are set for the selected channels. Keyframing these channels establishes a blending connection that will be discussed in subsequent steps.

6. In the Channel Box, set Rotate Y to -90.

   The aircraft is rotated 90 degrees from its motion path position.

7. Select the Rotate Y channel, then right-click and select Key Selected from the drop-down list.

   A keyframe is set for the aircraft.

   Additional channels appear in the Channel Box. When a keyframe is set for an object that already has motion path animation, the software automatically creates a connection to blend between the two animation types. These new channels are used to control the blend between the keyframe and motion path animation types. They control the blend for the Translation and Rotation attributes.

   

8. To set the remaining keyframes for the keyframe motion of the aircraft, use the table below as a guide, keeping in mind that you set the keyframes in the following order:

   • Set the frame in the Time Slider.

   • Set the Translate and Rotate values in the Channel Box.

   • Select only the channels for those values. Right-click on the selected name and choose Key Selected.

     

9. Click play on the Time Slider playback controls to play back the animation.

   The aircraft rises above the ground plane and then stops at frame 40.

   

The animation stops because the motion path animation was shut off when the blend attribute was automatically created when you set the first keyframe. The blend attribute values are set to zero by default. When the blend values are set to zero, the keyframe animation has full influence on the object, and the path animation is shut off. When the blend values are set to one, the motion path has full influence on the object and the keyframing is shut off. When the blend values are between zero and one, the aircraft’s motion is blended between the keyframe and motion path animation.

In the next steps, you keyframe the blending attributes so the blending begins at frame 30 and ends at frame 70. This blends the two animation types together over a period of 40 frames.

To blend between the two animation types

1. Set the Time Slider to frame 30.

2. In the Channel Box, ensure the blend values are set as follows:

   • Blend Add Double Linear: 0

   • Blend Motion Path: 0

3. Select both the Blend Add Double Linear1 and Blend Motion Path1 channels, then right-click on either name and select Key Selected from the drop down list.

   A key is set for the blend starting point for the aircraft. At frame 30 the two animation types will begin to blend together.

4. Set the Time Slider to frame 70.

5. In the Channel Box, set the following:

   • Blend Add Double Linear1: 1

   • Blend Motion Path1: 1

6. Select both the Blend Add Double Linear1 and Blend Motion Path1 channels, then right-click on either name, and select Key Selected from the drop down list.

   A key is set for the blend ending point for the aircraft. At frame 70 the motion path animation will have full influence.

7. Click play on the Time Slider playback controls to play back the animation.

   The two animation types are combined but the motion does not appear correct. The aircraft rotation flips upward momentarily when it begins to travel along the motion path.

   

   The interpolation type for the rotations during the blending is not set correctly.

Setting the pairBlend Rot Interpolation setting to Quaternions changes how the rotations are interpolated during the blend. In this example, Quaternions provides a better interpolation type when blending between the keyframe and motion path animation.

To edit the rotation interpolation type for blending

1. In the Channel Box, click on the pairBlend1 channel.

2. Scroll the Channel Box so you can view the Attributes for pairBlend1.

3. Set the Rot Interpolation setting to Quaternions by clicking on the Euler angles name with the left mouse button.

4. Click on the pairBlend2 channel.

5. Click on the Euler angles name in the Rot Interpolation attribute and choose Quaternions.

6. Click play on the Time Slider playback controls to play back the animation.

   The animation plays back smoothly. Observe how the blending also takes into account the rotation of the aircraft so it meets up with the motion path smoothly.

[7] Using Playblast to playback an animation

Playblast allows you to preview an animation by calculating the separate frames and playing them back in a multimedia player window based on the Playblast options. Playblast provides a more accurately timed playback than using the Time Slider.

To playback the animation using Playblast

1. Select the path curve, and then select Display > Hide > Hide Selection to hide the curve while you Playblast.

2. Select Window > Playblast.

   Playblast calculates the frames for the animation and then plays them back in the player window.

You have completed this lesson.

[8] Beyond the lesson

In this lesson you learned how to:

• Create a motion path animation using a NURBS curve as the motion path.

  When you draw your own curves remember that a curve has a defined start and an end point based on how you create it. If your object is initially positioned at the wrong end of the curve, you can reverse the direction of the curve by setting the Menu Set to Modeling and then selecting Edit Curves > Reverse Curve Direction.

  If your objects are not oriented correctly on the path initially, you can change the options in the Attach to Motion Path Options window (Animate > Motion Paths > Attach to Motion Path).

• Adjust the timing and rotation of an object when it travels along the motion path.

  In this lesson you were shown how to keyframe the roll (bank) of the aircraft. The Attach to Motion Path Options window provides an option called Bank. The Bank option rotates an object as it travels around curved portions of a motion path. It is useful for simple motion path animation.

• Blend between keyframe and motion path animation types on the same object.

  (For more information, search for pairBlend in the Maya Help.)

With keyframe animation, you key an attribute value to a time in the Time Slider. You repeat this process with different values at different times to animate the object.

When you must animate multiple objects or attributes that interrelate, setting keyframes can quickly become a complex task. Set Driven Key is a technique for driving one object’s or attribute’s animation from another attribute.

With driven keys, you relate an attribute value to the value of another attribute. You repeat this with different values to create a dependent link between a pair of attributes. A change in the driver attribute alters the value of the driven attribute. In this way the animation of the driven attribute doesn’t need to be manually set; it occurs automatically once the relationship between attributes has been established. This makes setting up some types of animations much more efficient. For example, you can use driven keys to make a door open when a character walks in front of it.

In this lesson, you will learn how to use Set Driven Key in order to animate a door rising upwards when a ball approaches it.

In this lesson you learn how to:

• Link the object attribute behavior between two objects which will link the movement of one keyframed object to another with no keyframes assigned.

• Use the Graph Editor to adjust the animation for the driven object.

[2] Lesson setup

In the following steps, you set a playback range that’s long enough to see the animation clearly. You also create the ball and the door, and position them in the scene view in preparation for the animation.

1. Make sure you’ve done the steps in Preparing for the lessons.

2. Create a new scene.

3. Go to the start frame.

4. Create a polygonal cube and name it Door.

5. With the pointer in the perspective view, press 5 (for Shading > Smooth Shade All).

   

6. Scale and position it roughly as shown. Have the bottom edge of the door lie roughly along the X-axis.

7. Create a small polygonal sphere and name it Ball. Scale and position it roughly as shown in the prior figure in the introduction. Have it sit roughly at 0, 1, 10 (X, Y, Z).

   

[3] Using Set Driven Key to link attributes

The following steps link the door’s movement to the ball’s movement using Set Driven Key.

To link the door’s movement to the ball’s movement

1. Select the door, then select Animate > Set Driven Key > Set.

   The Set Driven Key window appears with the door in the Driven list.

2. Click Translate Y in the Driven list.

   This is the attribute to be driven by the ball’s movement.

3. Select the ball in the scene view.

4. In the Set Driven Key window, click Load Driver.

   The ball appears in the Driver list.

5. In the Set Driven Key window, click Translate Z in the Driver list.

   This is the attribute that will drive the door’s movement.

   You can set a driven key only after you select an attribute in the Driver list and in the Driven list.

   

6. In the Set Driven Key window, click Key.

   This sets a driven key relationship that links the current Translate Z value of the ball to the current Translate Y value of the door. Whenever the ball’s Translate Z is at this position, the door’s Translate Y will be at its current position.

   The Time Slider is not involved in a driven key relationship and displays no red markers for keys.

7. Move the ball to the door’s position and then move the door above the ball.

   

   NOTE:

   The objects in these images have materials applied to give them color. To learn how to apply materials refer Shading surfaces in the Rendering lessons.

8. In the Set Driven Key window, click Key.

   This sets another driven key that links the current Translate Z value of the ball to the Translate Y value of the door.

9. Move the ball to the right of the door and then lower the door to its previous position as shown in the following figure.

   

10. In the Set Driven Key window, click Key.

    This sets another driven key that links the attributes.

    You’ve set three driven keys that link the attribute values at different positions. Maya interpolates the linked values to generate the values between the keys.

    If you drag the ball toward the door from either side, the door rises smoothly.

    Playing back the animation from the Time Slider doesn’t move the ball or the door. Driven keys link one attribute to another. They don’t link attributes to times in the Time Slider. However, if you were to animate the movement of the ball, the door would move based on the driven key relationship that has been set.

[4] Viewing the results in the Graph Editor

In the next steps you’ll examine the animation curve resulting from the driven keys you’ve set. If you are unfamiliar with animation curves and the Graph Editor, see Keyframes and the Graph Editor.

To view the set driven key results in the Graph Editor

1. Select the door.

   To display the animation curve for a driven key in the Graph Editor, you must select the object containing the driven attribute, not the object containing the driving attribute.

2. Select Window > Animation Editors > Graph Editor.

3. From the Graph Editor, select View > Frame > Frame All. The Graph Editor shows the driven keys that link the door’s Translate Y value to the ball’s Translate Z value. An example follows:

   

   The column of numbers on the left lists the driven attribute values. The row at the bottom lists driver attribute values. The animation curve shows the relationship between the values—the door’s Translate Y value rises as the ball’s Translate Z value approaches 0.

   You can use the Graph Editor to edit the shape of the curve to make the door rise faster, slower, and higher as the ball approaches it.

[5] Beyond the lesson

In this lesson you learned how to:

• Set driven keys to link one attribute’s values to another.

  A driven attribute is not directly affected when you play the animation. It is linked to a driving attribute’s value, not animation time. However, you can use regular animation keys, expressions, motion paths, or other techniques to animate the driving attributes. This indirectly animates the driven attribute.

You may find the following notes helpful when using Set Driven Key:

• You can set driven keys to control a driven attribute with multiple driving attributes. For instance, you can have a muscle bulge when an elbow rotates, and have the bulge increase when the wrist rotates.

When you set a keyframe (or key), you assign a value to an object’s attribute (for example, translate, rotate, scale, color) at a specific time.

Most animation systems use the frame as the basic unit of measurement because each frame is played back in rapid succession to provide the illusion of motion.

The frame rate (frames per second) that is used to play back an animation is based on the medium that the animation will be played back (for example, film, TV, video game, and so on.)

When you set several keys at different times with different values, Maya generates the attribute values between those times as the scene plays back each frame. The result is the movement or change over time of those objects and attributes.

In this lesson, you will use simple keyframing techniques to make a ball fly over a fence and bounce off the ground.

In this lesson, you learn how to:

• Set keyframes for animatable objects and their attributes.

• Use the Time and Range slider and Playback Controls to control the playback.

• Use keyboard shortcuts to set keyframes.

• Use the Graph Editor to view animation curves.

• Modify the animation of objects using the Graph Editor.

• Set preferences to increase the playback quality.

[2] Setting the playback range

In the following steps, you open the scene and set how long the animation will play.

To open the scene

1. Make sure to do the steps in Preparing for the lessons.

2. Open the scene file named Keyframing.mb.

   This file can be found in the GettingStarted2015LessonData\Anim directory that you set as your Maya project.

   The scene contains a ball object that is currently positioned on the X-axis near the edge of a ground plane.

   To animate the ball, you key its position at different times of the playback range.

   The playback range is defined by the Time and Range slider. The Time and Range slider controls allow you to playback or scroll through your animation or move to a specific point in time of your animation so you can set keyframes.

To set the playback range for the scene

1. Look over the playback controls, as shown in the figure below:

   

   The Time Slider displays the playback range and keys you’ve set for a selected object. Keys are displayed as red lines. The box at the right of the Time Slider lets you set the current frame (time) of the animation.

   The Playback Controls control animation playback. You may recognize the conventional buttons for play and rewind (return to the start time). The stop button appears only when the animation is playing. To find out which operation a button represents, hold the mouse pointer over it.

   The Animation Preferences button displays a window for setting animation preference settings such as the playback speed.

   The Range Slider controls the range of frames that play when you click the play button.

   The above items will have more relevance as you work through this lesson. After you complete this lesson, experiment with these items to learn more what they do.

   The playback range is currently set at a range of 1 to 24. At a default playback rate of 24 frames per second, the scene can play for one second. Because you’ll animate the ball for a few more seconds than this, you need to lengthen the playback range.

2. In both the Playback End Time box and the Animation End Time box, enter 72.

   A frame rate of 24 frames per second (fps) is the frame rate used for motion picture film. For video, the frame rate can be 30 fps (NTSC) or 25 fps (PAL) depending on the format being used.

   With a playback range of 1 to 72, you’ll be able to create three seconds of animation. (72 frames divided by 24 frames per second = 3 seconds.) This is enough time for the short animation you’ll create in this lesson.

[3] Setting keyframes

In the following steps, you use keyframes to set the starting and ending positions of the ball’s movement.

To set beginning and ending keyframes

1. Click the Go To Start button to go to the start of the playback range. This changes the current frame to 1.

2. Select the ball, then select Animate > Set Key. (Keyboard shortcut: s).

   This sets a key at frame 1 for all transform attributes of the ball. Transform attributes are the X, Y, Z move attributes. Although you animate only the translate X and Y attributes of the ball in this lesson, keying all transform attributes saves you time having to choose specific attributes to be keyed.

   In the Time Slider, notice the red marker at frame 1, known as a tick. This tick appeared when you set the key for frame 1. With the ball selected, ticks in the Time Slider indicate where you’ve set keys.

3. Go to frame 72. A convenient way to do this is to click the desired position in the Time Slider.

4. With the Move Tool, drag the ball’s X-axis handle to position the ball at the right edge of the ground as shown in the image below.

   

5. Set a key at frame 72. (Press s.)

6. Go to the start time and play the animation.

   From the two keys you’ve set, Maya creates motion between the positions. By default, the animation plays in a loop from frame 1 to 72. The ball travels through the fence at this stage.

7. Press the Stop button on the playback control to stop the animation after you view a few repetitions.

   You can drag the mouse back and forth (scrub) in the Time Slider to see the animation play back and forth at the speed you drag the mouse.

   If you were to display the scene with Panels > Layouts > Four Panes, only the active panel would show the ball moving.

To make the ball fly over the fence rather than pass through it, you need to position the ball above the fence and set a key there.

To set intermediate keyframes

1. Go to frame 33 or so—at the moment where the ball sits in the middle of the fence.

2. With the Move tool, drag the Y-axis handle of the ball until it sits slightly above the fence.

3. TIP:

   Throughout this lesson, tumble the perspective view or examine a front view to make sure the positioning is correct.

   

4. Set a key. (Press s.)

5. Play the animation.

   The ball now flies off the ground, over the fence, and back to the ground in a smooth arc between the keyed start, middle, and end positions.

6. Press the stop button to end the playback.

   In subsequent steps, play the animation after each key you set. It’s generally useful to check your work in progress after each key, especially when you are learning.

In the next steps, you’ll set keys to bounce the ball in the middle of the right half of the ground.

To set keyframes to make the ball bounce

1. Go to frame 50. At this moment, the ball sits in a position above the middle section of the right half of the ground.

2. Move the ball so it sits on the ground.

   

3. Set a key.

4. Go to frame 60.

5. Move the ball up again, but not as high as its peak height above the fence.

   

6. Set a key. When you play the animation, the ball travels over the fence and bounces on the other side.

   If you have a fast computer, you might notice that the animation plays too fast. By default, Maya plays the animation as fast as it can be processed. Because this scene is simple, the animation might play faster than the default film rate (24 frames per second).

   Do not be concerned that the animation plays with a halting or jerky motion. When you render all the frames of your animation for final production, the animation will be smooth. If you want to preview the animation at the smooth production speed (or nearly so), use Window > Playblast.

[4] Using the Graph Editor

For a more convincing animation, you need to bounce the ball more sharply off the ground and speed up the ball’s horizontal movement. You’ll use the Graph Editor to make both modifications.

The Graph Editor is an editor that graphically represents the various animated attributes in your scene. The animated attributes are represented by curves called animation curves. You edit animation curves in the Graph Editor.

To edit animation curves using the Graph Editor

1. With the ball selected, select Window > Animation Editors > Graph Editor.

   

   The Graph Editor displays several animation curves, one for each keyed attribute of the ball. The animatable attributes for the ball are listed in the left column. Specifically, it displays the attributes of the selected transform node of the ball.

   Each curve graphs how an attribute changes value during the animation. The column of numbers at the left represents attribute values that can be animated, while the row of numbers at the bottom represents time (frame) values. At each point on the curve, you can see the value of an attribute at a particular time. The small black squares on the curves represent points where you’ve set keys.

2. Shift-Select only the Translate X and Translate Y attributes in the left column of the Graph Editor.

   Now only the animation curves for Translate X and Translate Y appear in the Graph Editor.

   This simplifies the display. With too many curves present, it’s hard to see specific curves. When you use the Graph Editor, you usually focus on one or a few curves.

   TIP:

   To change the background or other colors in the Graph Editor, select Window > Settings Preferences > Color Settings, then expand the Animation Editors heading on the General tab. These settings let you change the Grid Axes, Grid Lines, and Background.

3. To center the display of the animation curves, select View > Frame > Frame Selection (in the Graph Editor window). If you want to see more detail in the graph, use your mouse to dolly and track the graph view.

   

   The green curve represents Translate Y, while the red represents Translate X. The color of each curve matches its attribute name. This color scheme is consistent throughout Maya for X, Y, and Z (red, green, blue).

   If you’ve never used a graph editor before, the relationship between a curve’s shape and the animation it represents might be hard to understand. With experience, you’ll quickly recognize how curve shape affects animation.

   In the above graph, the straight curve of Translate X indicates that the ball moves horizontally across the ground at a constant rate over time.

   The wavy curve of Translate Y indicates that the ball increases its height steadily until frame 33, dips more quickly until frame 50, then rises and dips again until frame 72.

   When the ball first bounces off the ground at frame 50, it seems to float and slip rather than rebound. The shape of the Translate Y curve illustrates why. Near frame 60, the curve is soft and rounded. The Translate Y values gradually decrease to the low point then gradually increase. The transition from decreasing to increasing values is smooth.

   The Graph Editor’s usefulness lies in the fact that you can edit the shape of the animation curves to edit the animation of any keyed attribute. To create a sharp bounce, you can edit the curve so that the transition from decreasing to increasing values is abrupt at frame 50. Specifically, you’ll create a corner at that key point rather than a rounded curve.

4. Select the point on the Translate Y (green) curve at frame 50.

   This causes a pair of tangent handles to appear at the point. Each end point of the newly displayed straight line is a tangent handle. The handles let you control the curvature near the key point.

   Animation curves have a few control structures for curve editing. You can do any of these operations:

   • Use the Move tool and middle mouse button to move a key point. You can alternatively use your keyboard to enter precise values for a selected key’s frame and value in the boxes above the graph area.

   • Use the Move tool and middle mouse button to drag the tangent handles and change the adjacent curvature.

     (You can shift-drag with the Move tool to constrain a move operation to a single direction.)

   • Use the Scale tool and middle mouse button to scale selected key points closer together or further apart.

   • Use the Graph Editor’s Tangents menu items to change the adjacent curvature. This is the operation you’ll use in the next step.

5. In the Graph Editor, select Tangents > Linear.

   This changes the curvature around the key point from rounded to cornered. Specifically, the setting you select specifies how the key point tangent handles lie at this key point. This affects the type of interpolation between key points.

   

6. Play the animation and you’ll see the ball bounce more sharply.

   To sharpen the bounce more, you need to edit the positioning of the tangent handles to steepen the curvature approaching the key point.

7. Select one of the tangent handles.

8. Select the Move Tool and then use the middle mouse button to drag the tangent handle upwards a little so you can see the how the curvature at the key point changes.

   By default, when a pair of tangent handles share a key point, they work as a unit. Move one and you move the other in an opposing direction. This is often desirable in an animation curve, because it ensures the curvature at that point stays symmetrical. Symmetrical curvature often helps prevent unusual animation shifts.

   In this case, however, you want to steepen the curvature’s approach toward the curve point in the same direction on both sides. You therefore need to break the symmetrical interdependency between the two tangents.

9. Undo your previous move of the tangent handle.

10. Select the key point at frame 50 (not a tangent handle).

11. In the Graph Editor, select Tangents > Break Tangents.

    This lets you move each tangent handle independently.

12. Select the right tangent handle and use the Move Tool to move it up a little. Do the same for the left tangent handle. Be careful not to select the key point.

    

    This sharpens the bounce to better simulate the effect of gravity and elasticity.

[5] Changing the timing of an attribute

The ball seems to move too slowly in its journey. In the following steps, you’ll use the Graph Editor to hasten its movement. Specifically, you’ll cause the ball’s animation to finish its journey in two seconds (48 frames) rather than three (72 frames).

TIP:

Widen the Graph Editor window as necessary to see the graph clearly. Also, dolly the view or select View > Frame > Frame Selection (in the Graph Editor window).

To speed up the animation of the ball’s movement

1. Drag a selection box around all key points of both curves.

2. Select the Scale tool.

3. Click and hold the middle mouse button anywhere in the graph at frame 1 (slightly to the right of 0).

   Notice the question mark icon. The location of this icon indicates the point from which scaling occurs. (Because you need to scale the animation inward toward frame 1, you need to start your drag operation at frame 1.)

4. Without releasing the mouse button, drag to the left until the right-most key points on both curves are positioned roughly at frame 48. (When selected, the right-most key points are yellow.)

   

   NOTE:You can also use the Region Tool to scale your curves. Select the Region Tool from the Graph Editor toolbar, select the region of curves you want, then drag the region handles (white boxes) to scale.

   This scales the curves symmetrically towards frame 1. The animation of the ball now plays from frame 1 to 48 rather than 1 to 72. The ball traverses the scene in less time, which, of course, means it moves faster.

   If you had started your drag operation from the middle of the frame range, the scale operation would have pulled the curves toward the middle of the frame range. You can snap the keypoints to whole values to keep the keyframes on a consistent timing.

[6] Fine tuning an animation

Now you can improvise adjustments to the animation on your own. For example, you might choose to speed the ball’s horizontal movement up to the first bounce but not thereafter. You might also decide to raise the peak height of the ball’s motion so that it doesn’t seem to hover over the fence unrealistically.

Whatever you choose to do, you’ll likely need to edit both the Translate X and Translate Y curves, not just one of them. Play the animation after each adjustment.

The following two figures show examples of curves after modification. The two graphs are identical, except the curve points are selected in the second figure. The second graph shows the position of the tangent handles.

If you want your curves to match the shape of the curves in the above figure, here’s what you would need to do:

To adjust the animation curves to match the above images

1. On the Translate X curve, delete the three key points between the two key points at the end. To delete keys, select the key points and press Delete. (The preceding figures show the curve after the points were deleted.) To delete the points, drag a selection box around them and press Delete.

   With fewer key points on the curve, it’s easier to maintain the curve’s smoothness for larger distances as you edit its shape. Small kinks in an animation curve can ruin an otherwise perfect animation, so it’s useful to remove key points that you aren’t using.

2. On the Translate X curve, select the left-most key point and move its right tangent handle down slightly. (Remember to use the middle mouse button when moving a handle or point.) Select the right-most key point and move its left tangent handle up slightly.

   Notice that the slope of the Translate X curve increases slightly in the early part of the animation, then tapers off toward the end. This causes the ball to accelerate slightly at the beginning of the animation, then decelerate after its first bounce.

3. On the Translate Y curve, remove the key point at frame 22. (The preceding figures show the curve before the point was removed.) This point wasn’t essential to the curve shape.

4. On the Translate Y curve, select the left-most key point and move its right tangent handle up slightly.

5. At the key point where the bounce occurs on the Translate Y curve, move the left tangent handle up a bit. This raises the high part of the curve left of that key point, which makes the ball rise higher over the fence.

6. If you want to change the shape of Translate Y curve but lack adequate control with the existing key points, you can add a key point at the position of your choice. (No key points were added in the prior figures.) To add a key, click the Add Keys Tool icon

   

   , select the curve, and middle-click the desired position on or off the curve.

[7] Deleting extra keyframes and static channels

As you set keys, you often create many unintended keys. For example, when you used the Set Key operation on the ball, Maya created keys on all transform node attributes of the ball, for instance Rotate Z, not just the intended Translate X and Translate Y attributes. The curves representing such attributes have unchanging values. The attributes are known as static channels.

You can identify static channels by examining animation curves in the Graph Editor. If a curve is horizontally flat its whole length, the value of the attribute it represents isn’t changing. The attribute is a static channel. Static channels slow Maya processing, so it’s beneficial to remove them in complex scenes.

To delete static channels

1. From the main menu, select Edit > Delete by Type > Static Channels.

This deletes all unnecessary keys for all objects in the scene.

In addition to static channels, you’ll often create excess keys—keys that aren’t being used to control the shape of a curve. Whenever you see three key points that lie in a straight line, the one in the middle is unnecessary. For example, in this lesson’s original Translate X curve, there were four redundant keys:

When you remove redundant key points, the shape of the curve doesn’t change and you speed up Maya processing.

[8] Using Playblast to playback an animation

When you play a scene, you see a rough approximation of the animation. The playback speed and quality is imprecise as compared to rendering each frame and playing the frames in sequence with a playback utility specifically designed for this purpose. The reason for this is that Maya processes the animation of each frame before display, while a playback utility simply plays previously processed and rendered images.

The more detail that Maya needs to process, the slower the playback. For example, playback will likely be slow for any scene that has several complex objects displayed with Smooth Shade All and Hardware Texturing.

To preview the animation with more accurate timing

1. Select Window > Playblast.

   For the next several seconds, Maya processes the entire animation frame by frame. When the process is complete, a playback window appears.

2. Click the play button in this window to watch the animation.

3. Close the Playblast window when you’re done.

[9] Beyond the lesson

In this lesson, you learned how to:

• Set keys for attributes, then use the Graph Editor to refine the animation and remove unnecessary keys. This is a typical workflow when keyframing.

  You can animate most any attribute in Maya, not just the Translate, Rotate, and Scale attributes of a surface. For example, you can animate the intensity of a light, the transparency of a surface, the rotation of a camera view, or the position of CVs.

• Work with the Graph Editor to adjust the animation attributes animation curves directly.

  The Graph Editor is the best tool for editing keyed animation by reshaping animation curves. You can use it to change key positions, add or remove keys, and alter the fluidity and symmetry of animation.

  Each key point on an animation curve has a Tangent setting that specifies the curvature leading into that point. The default Tangent setting (Auto) creates rounded curvature—useful for animating attributes that change smoothly over time. The Linear setting creates angular curvature, useful for a bounce effect or any other abrupt change in attribute value. Other Tangent settings are available for different animation effects. For example, a Stepped setting lets you make an instantaneous leap in value, useful when you want to flash a light off and on.

• Use the Time and Range slider to play back your animation.

  Although the Graph Editor is a popular animation tool, you can also cut, copy, paste, and delete keys directly in the Time Slider to edit animation. Select a key position in the Time Slider, then right-click to select the desired operation from a pop-up menu.

You may find the following techniques useful when keyframing your animations:

• There are alternative object display modes that quicken the display of animation in the scene view. When you select Shading > Bounding Box (from the panel menu in the scene view), Maya displays simple box-shaped geometry in place of the actual objects in your scene. The simpler shapes enable Maya to respond to any camera and object movement faster. The drawback is that you cannot edit the shape of the objects in this display mode.

• It is generally a recommended practice to animate a parent (group) node rather than objects themselves. By animating a parent node, you can avoid problems that occur when the animation of one object in a hierarchy conflicts with the animation in another part of the hierarchy.

This lesson provides a brief introduction to rendering in Maya. In this lesson, you learn how to:

• Assign shading materials to surfaces in the scene.

• Edit the color of shading materials.

• Apply simple textures to shading materials.

• Render both a single image and a sequence of images for an animation.

• Use Interactive Photorealistic Rendering (IPR) to perform test renders of the scene.

• Edit the Render Settings attributes to change the quality of the final results of an image.

• View a sequence of rendered frames for an animation.

[2] Open the scene for the lesson

In this lesson, you render a scene we’ve created for your use.

1. Make sure you’ve done the steps in Preparing for the lessons.

2. Open the scene file named apple.mb .

   This file can be found in the GettingStarted2015LessonData\Rendering directory that you set as your Maya project:

   

   The scene contains an apple sitting on a plane, with another plane as the background. A camera in the scene is animated to revolve around the apple at varying distances. (As an alternative to using the scene apple.mb, you can create a similar scene with your own objects.)

3. Select Renderer > Viewport 2.0 from the panel menus.

   You will view the scene view through the Viewport 2.0 renderer.

   IMPORTANT:In order to use Viewport 2.0 , you must use a graphics card that is Viewport 2.0 compliant. For a list of certified hardware, please see http://www.autodesk.com/hardware.

4. Select Window > Settings/Preferences > Preferences.

5. Click the Time Slider category and make sure the Playback speed option is set to Real-time (24 fps) so your animation will playback at the default rate of 24 frames per second.

6. Close the Preferences window.

   You won’t use the animated camera until later in the lesson. In the next steps, you color the apple and the planes by creating shading materials.

[2] Creating shading materials for objects

A shading material is a collection of attributes that you apply to a surface to control how the surface appears when it is rendered. Shading materials include such attributes as color, shininess, and texture. The following table outlines the materials you’ll be working with:

When you open the apple.mb file, it initially displays the apple and the planes as wireframes (Shading > Wireframe). This is the default display mode for objects in a scene view.

To create materials for the apple stem

1. In the perspective view, select Shading > Smooth Shade All (hotkey: 5).

   

   The apple and the other surfaces appear with a default gray, smooth shading material, lit using default lighting. Default lighting occurs when no other lights have been placed in the scene.

2. In the perspective view, select the apple stem by clicking its geometry. (Be sure that only the apple stem is selected.)

   

3. From the Rendering menu set, select Lighting/shading > Assign New Material.

   The Assign New Material window appears.

4. Click Lambert.

   The Attribute Editor appears for the Lambert material.

   A Lambert material creates a matte surface without shiny highlights. You will learn more about materials and their attributes in a later lesson.

5. Click the gray box to the right of Color.

   

   The Color Chooser window appears.

6. Click inside the color wheel and drag to a brown color.

   The color you select in the Color Chooser is applied to the apple stem.

   

   Move your mouse off the Color Chooser to exit.

7. In the Attribute Editor, rename the lambert shading material to appleStem_lambert.

To create materials for the apple

1. Right-click the apple and select Assign New Material from the marking menu.

   The Assign New Material window appears.

   NOTE:Make sure you have the apple selected and not the stem or the new material and color will be assigned to the stem.

2. Select Phong.

   The Attribute Editor updates to display the attributes for the Phong material.

   A Phong material gives the apple a shiny appearance.

3. Click the gray box to the right of Color.

   The Color Chooser window appears.

4. Click inside the color wheel and drag to a red color.

   The apple’s surface updates to the same color you select in the Color Chooser.

5. In the Attribute Editor, rename the Blinn shading material to appleSkin_blinn.

To create materials for the counter and wall

1. Right-click the background plane and select Assign New Material from the marking menu.

   The Assign New Material window appears.

   NOTE:Make sure you have the background plane selected and not the apple or the new material and color will be assigned to the apple.

2. Select Lambert.

   The Attribute Editor displays the attributes for the Lambert material.

3. Click the gray box to the right of Color.

4. In the Color Chooser window, click inside the color wheel and drag to a light blue color.

   The color you select in the Color Chooser is applied to the plane.

5. In the Attribute Editor, rename the Lambert shading material to wall_lambert.

6. Right-click the surface that the apple is resting on and select Assign New Material > Lambert.

   The Attribute Editor displays the attributes for the Lambert material.

   NOTE:Make sure you have the surface plane selected and not the background plane or the new material and color will be assigned to the background plane.

7. Click the gray box to the right of Color.

8. In the Color Chooser window, click inside the color wheel and drag to a beige color.

   The color you select in the Color Chooser is applied to the plane.

9. In the Attribute Editor, rename the Lambert shading material to counter_lambert.

   

   The counter, wall, and apple stem all have a matte Lambert surface, while the apple has a shiny Phong surface. There are many other attributes you can set to change the appearance of these objects, which you’ll explore in the next section.

[3] Refining shading materials for objects

You can refine the shading materials in the scene to make the objects appear more realistic. In the next steps you connect (or apply) a procedural texture to the counter, and a ramptexture to the apple. These textures are connected to the color attribute of the shading material for each surface to provide natural surface variation. When you connect textures, you create shading networks. You’ll learn more about shading networks in a later lesson.

A procedural texture is a 2D or 3D texture calculated based on an algorithm or mathematical formula. It can be useful for creating random patterning. A ramp texture is a 2D texture or color gradient in which the color or grayscale value changes across the image.

To connect a procedural texture to the counter surface

1. In the perspective view, right-click the counter surface and select Material Attributes.

   The Attribute Editor for the counter_lambert material appears.

2. To the right of the Color slider, click the Map button

   

   The Create Render Node window appears and lists the various textures you can connect to the Color attribute of the Lambert material assigned to the counter surface.

3. In the Create Render Node window, select Maya > 3D Textures > Granite.

   

   The procedural texture gives the counter the look of a stone granite counter top when it is rendered, and provides the context for the scene.

4. In the Attribute Editor, under Granite Attributes change the Filler Color from the default reddish-brown to a beige color as follows:

   • Click the color box to the right of Filler Color.

     

   • In the Color Chooser window, select a beige color.

5. Press 6 to view the workspace in textured mode to see visualize the granite texture in the scene view.

To connect a ramp texture to the apple surface

1. Right-click the apple and select Material Attributes from the marking menu.

   The Attribute Editor updates to display the appleSkin_blinn material properties.

2. To the right of the Color slider, click the Map button.

   

   The Create Render Node window appears and lists the various texture patterns you can connect to the Color attribute of the Blinn material assigned to the apple.

3. Select Maya > 2D textures > Ramp.

   

   This texture creates a gradation through a series of selected colors. Applying the ramp texture provides the apple with a realistic variation in surface color.

4. In the Attribute Editor, under Ramp Attributes, change the Type to U Ramp.

   The Ramp Type indicates the direction of the color gradient. A U ramp applies the gradient in a linear, vertical direction across the object.

5. Add another color component by clicking within the ramp.

   A new set of color handles appears in the ramp, for a total of four color components.

   

6. To change the ramp colors, click the top circular color handle (to indicate which color you want to modify), then click the color box to the right of Selected Color to display the Color Chooser window.

   

7. Click inside the color wheel and drag to a very dark brown for the first ramp color.

8. Repeat steps 6 and 7 for the other three ramp colors. For the two middle ramp colors, select a dark red. For the last ramp color, select a deep olive green.

9. Use the circular color handles to reposition each component as shown below:

   

   The position of these handles and the corresponding colors affect the location and breadth of the color within the gradient on the apple’s surface.

10. Save your work.

    In the next section you render your scene to view the textures and materials you’ve assigned to the objects.

[4] Maya renderers

So far, you’ve seen the results of shading the apple and other surfaces in the scene view. In this view, Maya uses your computer’s graphics hardware to display the shading and textures.

Next, you use a renderer to create your final rendered images. In this lesson, you explore Interactive Photorealistic Rendering (IPR) as well as rendering using the Maya Hardware 2.0 renderer.

Rendering time is dependant on the complexity of surface geometry, shaders, lighting and other visual elements present in the scene.

The following table outlines the different types of renderers in Maya and what each is used for:

The Render View window

When you render your scene the rendered image appears in its own window called the Render View. By default, the Render View uses the same camera as the Scene View (persp), but includes particular rendering capabilities.

The following table shows the differences between the Render View and the Scene View:

[5] Rendering a single frame using IPR

In this section, you work with IPR (Interactive Photorealistic Rendering) for mental ray rendering.

The advantage of rendering with IPR is that, after you render an image, you can adjust the shading and lighting attributes of the scene and then quickly update part or all of the rendered image to review the effect of your changes. IPR is useful for iterations when you need to fine-tune specific attributes. Updates to the image are not always instantaneous, but they are full quality.

Using the mental ray for Maya renderer

To use IPR for mental ray rendering, you must first select the mental ray for Maya renderer.

To turn on the mental ray for Maya renderer

1. In the main menu, select Window > Rendering Editors > Render Settings (or click the Render Settings icon in the Render View window).

   

2. In the Render Settings window, set Render Using setting to mental ray .

   

NOTE:If mental ray does not appear under the list of renderers, you must load the mental ray plug-in via the Plug-in Manager. Select Window > Settings/Preferences > Plug-in Manager and select Loaded for the Mayatomr.mll plug-in.

To render the scene using IPR

1. In the perspective view, select View > Camera Attribute Editor to display the attributes for the camera.

   You need to specify the exact region of the perspective view you want to render.

2. In the Attribute Editor, open the Display Options section and turn on Display Resolution.

   A grey rectangular border shows the region to be rendered. This region defines the area of the final image, and allows you to decide what appears or does not appear in the final image. (The left and right borders of the rectangle may be positioned at the edge of the window.)

   

3. Select Render > IPR Render Current Frame (or select the IPR render current frame button on the Status Line).

   The Render View appears as follows.

   

   The message displayed at the bottom of the IPR Render View window states “Select a region to begin tuning”. In the next step, you create a subregion of the image to render using IPR.

4. In the Render View, select View > Frame Image to resize the Render View window so it fits closely to the rendered image.

To select a subregion to render using IPR

1. In the Render View, drag a selection box around the small area surrounding the apple, counter, and wall as shown:

   

   When using IPR, this selected region updates as you alter any shading, texture, or lighting attributes. Selecting a smaller region quickens the update. You can select regions throughout the image to see those areas update.

2. In the scene view, right-click the wall and select Material Attributes to display the Attribute Editor for the Lambert shader you applied to the wall.

3. Click the Color box and change the color to green.

   The area within the selected region of the Render View updates immediately as you alter the color; the wall turns green.

   When you drag within the color wheel of the Color Chooser window, the selected region updates occur immediately.

   

   NOTE:

   If the region does not update, in the Render Settings window, turn the Raytracing option off.

   (You won’t alter any other attributes in this lesson. The purpose of the lesson is to learn the process of rendering, not to perfect the results at this point.)

So far, you’ve used IPR to see changes you made to a shader. If you add lights to the scene rather than use the default lighting, you can also use IPR to help adjust the lighting.

[6] Rendering a single frame using Maya Hardware

In this section, you render the current frame using Maya Hardware 2.0.

Maya Hardware 2.0 allows you to set many options for your render, such as the object type filter (for example, if you only want to render your polygons and lights and exclude your cameras), to set the gamma correction, enable ambient occlusion or anti-aliasing and so forth.

Using Maya Hardware 2.0

To turn on the Maya Hardware 2.0 renderer

1. In the main menu, select Window > Rendering Editors > Render Settings (or click the Render Settings icon in the Render View window).

   

2. In the Render Settings window, set the Render Using setting to Maya Hardware 2.0.

   

Selecting Maya Hardware 2.0 options

Click the Maya Hardware 2.0 tab to view the available options.

Setting the object type filter

1. Expand the Batch Render Options section and then the Object Type Filter section.

2. De-select all options with the exception of NURBS Surfaces and Polygons to render only your apple model, the counter top plane and the wall plane.

Enabling anti-aliasing

1. Expand the Multisample Anti-aliasing section.

2. Select Enable to enable anti-aliasing.

3. Select 16 from the Sample Count drop-down box. Depending on your graphics card, this may be the highest level of anti-aliasing.

Rendering the frame

1. Click

   

   in the status line to render the current frame.

   

You can re-adjust the anti-aliasing Sample Count, or experiment with the other options as you like, and re-render to see the difference in results.

[7] 2.0 Rendering using the Maya Hardware 2.0 renderer Batch

In this section, you render the entire animation to disk. You must first switch camera views so you can render the scene from the point of view of the camera that was animated for this lesson. When animating a camera it’s a good practice to create a second camera to animate, rather than animating the default persp camera. In that way you can return to the default perspective view should it become necessary.

Rendering the entire animation can take a lot of time, so it is useful to first test render a few frames to your monitor and examine the results.

Once you are satisfied with the quality of a few rendered frames, you can render the entire animation to disk.

To switch camera views and playback the animation

1. In the perspective view, select Panels > Perspective > apple_camera.

   The view updates to display the scene as seen through the lens of the apple_camera.

2. Click the Play button in the Timeslider playback controls.

   During playback, the animated camera tracks and tumbles about the apple.

3. Stop the animation at a frame you want to test render.

To test render the current frame of animation

1. In the Render View window, select Maya Hardware 2.0 from the drop-down list.

2. Select Render > Render > apple_camera.

   This menu item uses the hardware 2.0 renderer to render a single frame of the scene from the point of view of the animated apple_camera.

3. Go to frame 120 of the animation, where the apple is viewed in a different position.

4. In the Render View, select Render > Render > Current (apple_camera).

   Ensure that the rendered image looks good at this frame also.

Now that you’ve checked a pair of rendered frames that represent the entire animation, you are ready to render the entire animation sequence. In your own projects, you might want to test render several frames, particularly where new shading and lighting elements occur in the animation.

[8] rendering a sequence of animation frames

After you model, animate, and color your scene, you set several Render Settings options and then use the mental ray renderer to batch render part or all of the animation’s range of frames to files on disk. Each file represents a single frame (image) of the animation.

To set the Render Settings for batch rendering

1. In the Render View window, select Options > Render Settings to display the Render Settings window.

2. In the Render Settings window, select the Common tab.

3. In the File Output section, set the following options:

   • File Name Prefix: Type the name Apple. This name will be the base of the filenames created by batch rendering.

   • Image Format: Select Maya IFF (.iff), Maya’s standard image file format. You can use the .iff format for any further work you need to do, including previewing and compositing the animation. If you require a different format, you can specify it instead of .iff in the Render Settings.

   • Frame/Animation ext: Select name.#.ext. This specifies that the filenames will have the format prefix.frameNumber.fileFormat. For example, batch rendering the entire 200-frame animation will create Apple.0001.iff, Apple.0002.iff, and so on through Apple.00200.iff.

   • Frame padding: Enter 4. This causes the frameNumber part of the filenames to be four digits prefixed with 0s. For example, the filenames will be Apple.0001.iff through Apple.0200.iff.

The four-digit padded filename is compatible with many image playback programs, for example, Maya’s FCheck utility. Image playback programs let you view rendered animation sequences on your monitor at real-time speed.

4. In the Frame Range section, set the following options:

   • Start frame: Enter 1, the first frame of the animation sequence to be batch rendered.

   • End frame: Enter 60, the last frame to be batch rendered. (Rendering all 200 frames may be time-consuming.)

5. In the Renderable Cameras section, set the following option:

   • Renderable Camera: Select apple_camera from the drop-down list to indicate which camera view to render.

6. In the Image Size section, select 640x480 from the Presets drop-down list.

   For the remaining options in the Render Settings window, you’ll use the default settings.

   After you set the Render Settings, the top portion of the Common tab shows the correct path and filenames for the files to be created during batch rendering. Check that this information is correct.

   

7. Close the Render Settings window.

To batch render animation frames

1. Save the scene.

   It’s a good practice to save the scene before batch rendering. This is useful if, after batch rendering, you need to change any display settings and render again. By saving the scene prior to batch rendering, you can examine the scene to learn which option settings were in effect at the time you batch rendered.

2. From the Rendering menu set, select Render > Batch Render.

   Batch rendering 60 frames of a simple scene takes a few minutes. A complex scene may take hours per frame, depending on the speed of your computer.

To check the status of the batch render

1. While Maya is rendering, select Window > General Editors > Script Editor. Expand the size of the Script Editor window. The window shows a completion log for the frames being rendered.

   Maya puts the resulting files in a default images directory. The files have the following names:

    Apple.0001.iff
    Apple.0002.iff
    Apple.0003.iff
    ...
    ...
    Apple.0050.iff
   

   The images directory is located in the same path as the scenes directory. You can have Maya save to a different path by changing the project setting. See the Maya Help for further information on projects.

2. Close the Script Editor when the following message appears:

   // Result: Rendering Completed. See mayaRenderLog.txt for information. //

   The mayaRenderLog.txt file contains rendering statistics for advanced users.

[9] Viewing a sequence of rendered frames

You can use Maya’s FCheck image viewing utility to view the batch-rendered images at a speed that approximates video or film.

To use FCheck to view a sequence of rendered frames

1. Select File > View Sequence.

   The File Browser window appears.

2. Using the File Browser, navigate to the images directory for your current project (or wherever you saved the rendered sequence of images for the Apple).

3. Click the image file Apple.0001.iff to select the first image in the sequence and then click Open.

   The FCheck image viewing utility appears and the rendered sequence of 60 frames plays back as an animated loop.

4. Close the window after viewing the animation.NOTE:

   The FCheck rendering utility has playback, display, and other options you can select from your keyboard. Details are available from the FCheck Help menu.

[10] Beyond the lesson

In this lesson, you were introduced to some of the basic concepts for rendering an image. In this lesson you learned that:

• Surfaces are assigned shading materials to provide basic attributes such as color, shininess, reflectivity, and so on. Each shading material has unique characteristics that can be modified to suit your requirements.

• You can additionally assign a texture map to some of the shading material attributes so that your objects appear more realistic.

• Maya provides several methods for rendering an image. You can render using the mental ray® for Maya® renderer, the Maya Software renderer, the Maya Hardware renderer, or the Maya Vector renderer. Each type of renderer has specific advantages and uses.

• You can choose the size and quality for a rendered image prior to rendering based on your specific needs and requirements.

• You can render a single image or a sequence of images from an animation.

• You can view one image, or a sequence of rendered frames using the FCheck utility.

As you render scenes, consider the following issues:

Batch rendering

In this lesson, you used the Maya Hardware 2.0 renderer to check the image quality of two frames before you started to batch render. When you create scenes with sophisticated animation, it’s useful to batch render with low-quality resolution to check the animation accuracy before batch rendering with production-quality resolution. For instance, you might preview your animation with the frames resulting from batch rendering at a small image size (320 by 240) or with a lower anti-aliasing sample count.

You don’t need to use the batch renderer to render single frames from your scene to disk. From the Render View window, select File > Save Image.

Hardware rendering

Hardware rendering leverages the power provided by hardware graphics cards to render your images. The benefits of hardware rendering include the ability to batch render frames more quickly than with software rendering, and rendering specific particle effects not possible through software rendering. For more information about hardware rendering particles, see Rendering particles in the Maya User Guide.

Hardware rendering is used in the scene view, and Viewport 2.0 allows for high interactivity for complex scenes with many objects as well as large objects with heavy geometry. You can also batch render using this hardware renderer by selecting the Maya Hardware 2.0 renderer from the Render Settings window.

Hardware rendering has its own limitations when compared to software rendering. For more information on hardware rendering, see the Maya Help.

Using render passes

It's often useful to render attributes of your scene in different passes and combine them using compositing software. When using the mental ray for Maya renderer, you can render each of diffuse, shadow, reflection, specular, and ambient occlusion in a separate pass and then composite the passes afterwards. You can select a subset of the objects or lights in your scene to contribute to each render pass. You can render an unlimited number of render passes, and then group them into logical groups called render pass sets. For more information about render passes, see Multi-render passes in the Maya User Guide.

Normal mapping is a technique in which you use a high resolution mesh to generate a map for a low resolution mesh. High resolution meshes are made of more complicated geometry and can be very taxing in an environment where resources are at a premium (for example, in a large scene with other high poly objects, or on a system with limited processing power). As a result, performance can suffer greatly. Normal mapping is commonly used in these situations to capture the detail of a high resolution mesh with the geometry of a low resolution model.

A normal map differs from a texture map in that it produces a multi-channel image (shown below) based on the normals of the high resolution (source) mesh. This information is used to light the mapped details on a low resolution (target) mesh convincingly, even though the surface itself is relatively flat.

In this lesson you learn how to:

• Create and apply a normal map.

• Display the poly count for a scene.

• Set the Search Envelope for a target mesh.

• Set Default Rendering mode and High Quality Rendering mode.

[2] Lesson setup

To ensure the lesson works as described, do these steps before beginning:

1. Make sure you’ve done the steps in Preparing for the lesson.

2. Select the Rendering menu set.

3. Select Renderer > Default Quality Rendering from the panel menu.

[3] Open the scene for the lesson

To create a normal map you need two files, the source and the target. The source model is generally a higher resolution and more detailed version of the target model. The target has the geometry you actually want for your scene.

To open the high resolution model

1. Select File > Open Scene.

2. Navigate to GettingStarted2015LessonData\UVMapping, select Toad_hi_res.mb and click Open.

   A high resolution polygonal toad model appears in the scene.

   

3. Tumble the view around the toad model.

   Maya may respond slowly because the mesh is highly detailed. You can see exactly how detailed it is by turning on the Poly Count display.

To turn on the Poly Count display

1. Select Display > Heads Up Display > Poly Count.

Statistics about the scene appear in the top left corner of the main viewport. This model consists of over a hundred thousand faces just for the head and upper torso. Loading such a high resolution model into the scene is impractical for performance purposes.

Now compare the high resolution mesh with the low resolution alternative.

To import the low resolution model

1. Select File > Import.

2. Navigate to GettingStarted2015LessonData\UVMapping, select Toad_lo_res.mb, and click Import.

   A low resolution polygon model loads on top of the high resolution toad model.

3. Select the high resolution model and hide it by pressing

   Ctrl+ h.

The low resolution model is much more manageable in size with just over 1500 faces. However, while it maintains the basic shape of the high resolution toad, it lacks much of the detail.

[4] Creating a normal map

A normal map is a type of transfer map, meaning that it is a texture created from a polygon object. Different transfer maps handle the conversion from polygons to textures in different ways. A normal map captures the surface normal information of the source mesh and uses it to light the target mesh.

To set a base material for the target mesh

1. Right-click the mesh and select Assign New Material from the pop-up menu.

   The Assign New Material window appears.

   

2. In the list of materials, select Blinn.

   Maya applies a default blinn shader to the low resolution mesh.

   

3. Close the Attribute Editor.

To show the high resolution mesh

1. Open the Outliner (Window > Outliner).

2. In the Outliner, select hi_res_toad.

3. In the main menu bar, select Display > Show > Show Selection.

   Both meshes appear in the scene overlapping each other.

4. Deselect the high resolution mesh.

To create a normal map

1. Select Lighting/Shading > Transfer Maps.

   The Transfer Maps window appears.

   The Transfer Maps window lets you create various textures based on mappings from polygon models. First you need to assign the source and target meshes for the transfer.

2. In the Outliner, select Toad_lo_res:lo_res_toad.

3. In the Transfer Maps window, in the Target Meshes section, click Add Selected.

4. In the Outliner, select hi_res_toad.

5. In the Transfer Maps window, in the Source Meshes section, click Add Selected.

Next you need to set the Search Envelope.

The Search Envelope represents the volume of the target geometry to consider for the texture. Whatever part of the source mesh between the Search Envelope and the target mesh is mapped to a texture.

Generally you want the Search Envelope to encompass your entire source mesh so you don’t miss any detail.

To set the Search Envelope

1. In the Transfer Maps window, in the Target Meshes section, set the drop-down underDisplay to Envelope.

   The low resolution toad is replaced by a translucent red mesh.

   This red mesh represents the Search Envelope.

2. Drag the slider under Search envelope (%) to the right.

   The red mesh grows.

3. Drag the slider so that the red mesh barely encompasses all of the high resolution mesh without leaving any white spots (excluding the eyes). You can also enter a value in the box next to the slider. In this case, a value of 4.3 yields just enough coverage around the two meshes.

   

4. Set Display back to Mesh.

Now you can set the normal map options.

To set the normal map options

1. In the Transfer Maps window, under Output Maps, click Normal.

   

2. In the Normal Map text field, click the browse icon (

   

   ).

   A file browser appears.

3. Navigate to GettingStarted2015LessonData\UVMapping and enter the name toad_texture.

4. Set File Format to DDS (dds).

5. Click Save.

6. In the Transfer Maps window, under Connect Output Maps, set Connect maps to to Assigned shader.

7. Under Maya Common Output, set Map width and Map height to 1024 and Sampling quality to Medium (4x4).

8. Click Bake and Close.

   Maya generates a normal map.

   NOTE:

   It may take a few minutes for Maya to generate the normal map.

[5] Viewing a normal map

Now that Maya has generated the normal map, you need to change the render mode to High Quality Rendering mode to see it.

To view the normal mapped texture

1. Select the high resolution toad model and hide it by pressing Ctrl+ H.

2. In the panel menu, select Renderer > High Quality Rendering.

   Now you can see the low resolution model with the detail of the high resolution model applied as a texture.

3. Tumble the view around the toad.

   The light on the surface reacts appropriately to all the details on the texture, without any loss in performance.

4. To remove the statistics at the top of the workspace for the next lesson, de-select Display > Heads Up Display > Poly Count.

NOTE:In addition to the High Quality viewport, you can also view normal maps in Viewport 2.0. Select Renderer > Viewport 2.0 to switch to Viewport 2.0. For more information, see Visualize interactively in Viewport 2.0 in the Maya user guide.

[6] Beyond the lesson

In this lesson you learned how to use a high resolution model to create a normal map for a low resolution model. You learned how to:

• Display the poly count for a scene.

• Set the source and target for a normal map.

• Set the Search Envelope.

• Switch between Default Quality Rendering and High Quality Rendering.

You can also try applying other types of transfer maps to a low polygon model. Each mapping feature gives you slightly different looks on your low polygon model. For more information about transfer maps, see Lighting/Shading > Transfer Maps.

While texturing a flat object is fairly straightforward, texturing an object with curves can pose some unique problems. How do you paint a 2D texture on a curved surface? How do you deal with a texture warping over bumps and grooves? If you try to break apart the UV mesh as in Lesson 1, you can potentially end up with hundreds of small pieces.

To deal with these problems, artists typically use a workflow called unfolding. Unfolding a UV mesh refers to the process of cutting a seam in the UV mesh (a mesh made up of UVs similar to how a polygon mesh is made of vertices) and then unfolding along that seam. The process is similar to cutting a seam along a shirt and laying it flat on a table. By laying out the UVs this way, you can easily paint a texture on the 2D surface, which you can then wrap around the model.

In this lesson you learn how to:

• Divide a mesh into separate parts for texturing.

• Assign a basic checker pattern to judge the quality of a mapping.

• Create a planar mapping.

• Cut UV edges.

• Unfold a UV mesh using the Unfold option.

• Fix an unfolded mesh using the Smooth UVs tool.

[2] Lesson setup

To ensure the lesson works as described, do these steps before beginning:

• Make sure you’ve done the steps in Preparing for the lesson.

• Open the scene file named Soldier.mb.

  This file can be found in the GettingStarted2015LessonData\UVMapping directory that you set as your Maya project.

  The scene contains a polygon soldier.

[3] Dividing the mesh

When working with UVs, it is useful to divide the workspace so you can see both the model and the UVs at the same time.

To view the soldier model and its UVs side by side

1. In the panel menu, select Panels > Saved Layouts > Persp/UV Texture Editor.

   The perspective view and UV Texture Editor appear side-by-side in the viewport.

If you select the polygon soldier you will notice that the UVs for the body, arms, and legs are scattered in a pattern that doesn’t resemble the actual model. This isn’t very helpful for painting a texture map.

To simplify the job, you need to divide the mesh into multiple pieces that you can then texture individually. Generally, you want to divide the mesh into pieces that can be unfolded into approximate square or rectangle shapes. This requires some pre-planning.

In this lesson you divide the body mesh into a torso, arms, and legs.

To divide the mesh into pieces

1. In the panel menu select Panels > Orthographic > front.

   The perspective view changes to an orthographic front view of the soldier.

   

2. Right-click the mesh and select Face from the marking menu.

3. Drag-select the faces on the right arm up to the shoulder.

   

   The drag-select operation also selects the faces on the back of the arm.

   TIP:Switch to perspective mode and rotate around the arm to make sure all of its faces are selected. You may want to dolly in on areas like the underarm to make sure your selection only includes faces from the arm. If you find any unselected faces or faces that should not be part of your selection, you can Shift-click to add or remove them.

   

4. Select Mesh > Extract.

   Now if you change the selection mask back to Object, you can select the hand separately from the rest of the body.

5. Repeat steps 2-4 for the following areas (use the pictures as reference for the boundaries of each extraction).

   

This leaves you with individual meshes for the arms, legs, and chest. The head, feet, and hands have already been done for you. This division allows you to texture each part individually.

[4] Creating a planar map

To texture an organic object, you must start by creating a planar mapping as a base, which you can then unfold.

To create a planar map for the torso

1. Right-click the torso and select Object Mode from the marking menu.

2. Select the torso.

3. Select Create UVs > Planar Mapping >☐.

   The Planar Mapping Options window appears.

4. Select Edit > Reset Settings.

5. Set Project from to Z axis.

6. Click Project.

   

   Maya creates a new UV mapping for the torso. If you look at the UV Texture Editor, you can see the new UVs look like a flattened version of the front of the chest. At first glance this may seem perfect, but there’s a major problem here that you need to change the UV Texture Editor view to shaded mode to see.

To turn on shaded UV display

1. In the UV Texture Editor, click the Shade UVs icon (

   

   ), or select Image > Shade UVs.

   In shaded UV mode, overlapping faces appear red while non-overlapping faces appear blue.

   

   Notice that all the faces for the torso are red. This is because the faces of the front and back of the torso are overlapping. If you tried to apply a texture to the UV mesh like this, you would get the exact same image on the front and the back of the torso.

   To fix this, we need to unwrap the texture so that front and back no longer overlap.

[5] Unfolding a UV mesh

Unfolding a UV mesh is the process of cutting a mesh so that you can lay its entire surface area flat. However, before you do this, you want to make sure your UVs are spread out evenly along the surface. You can do this by applying a basic checker pattern to the mesh.

To apply a checker pattern to the torso

1. Right-click the torso and select Assign New Material from the pop-up menu.

   The Assign New Material window appears.

2. Select Lambert.

3. Open the Attribute Editor.

4. In the lambert tab, set the lambert field to checker_pattern.

5. Click the box next to Color.

   The Create Render Node window appears.

6. Select Checker.

7. Press 6 to enter Smooth Shade mode.

   The torso is covered in a checker pattern.

   

8. In the panel menu, select Panels > Perspective > persp.

From the front view, the checker pattern looks roughly even with very little distortion. This indicates that the spread of UVs is fairly even. An even spread of UVs is important to avoid texture warping when you apply your texture. In some cases you may need to experiment with different planar mappings to give you the best base to start with.

However, the planar projection isn’t perfect. If you look at the sides of the torso, from the armpits to the waist, you can see some warping. This is the ideal place to cut the UV edges for unwrapping.

To cut the UV edges

1. Right-click the vest and select Edge from the marking menu.

2. Select all the edges in the line that runs from under the arm, down the side of the soldier’s body to the bottom of the vest. You can do this by double-clicking edges along this path until they are all selected.

   

   TIP:There are many small edges that must be included in your selection. Dolly, tumble and track the camera to see the edges on the underside of the belt and in the underarm region.

3. Shift-select the corresponding edge on the other side.

   An edge loop on both sides should be selected now.

4. In the UV Texture Editor, select Polygons > Cut UV Edges.

Now you are ready to unfold the mesh.

To unfold the torso

1. Right-click the torso and select UV.

2. Shift-select one UV at the inside tip of each vest strap, along the unfold line.

3. In the UV Texture Editor, select Polygons > Unfold >☐.

   The Unfold UVs Options window appears.

4. Select Edit > Reset Settings.

5. Set Pin UVs to Pin selected UVs.

   A pinned UV does not move when a UV mesh is unfolded. In general, you want at least one pinned UV when unfolding because it gives the unfold process a point of reference. This is similar to placing a pin in a piece of fabric so that it does not unfurl out of control as you unfold it.

6. Click Apply and Close.

Maya lays the UV mesh out across the UV space. Parts of it may fall outside the 0-1 texture space, but that’s fine for now. More importantly, notice that the pattern is much more even across the mesh now.

Unfortunately, while you’ve minimized the distortion, you’ve also create a visible seam where you cut the UV edges. This is unavoidable. In general it is best to put your seams in the least visible places. In this case, the seams will be obscured by the arms most of the time and therefore won’t be as noticeable.

[6] Adjusting the checker pattern

Although not always necessary, it is often helpful to increase the number of squares in your checker pattern. This can help you to more easily spot deformities in the pattern.

To increase the number of squares in the checker pattern

1. Right-click the torso and select Object Mode from the marking menu.

2. Select the torso in the perspective view.

3. Open the Attribute Editor and navigate to the checker_pattern tab.

4. Click the box next to Color.

5. In the place2dTexture tab, set Repeat UV to 10, 10.

   The number of squares on the torso increases.

   

[7] Outputting UVs

Now that you have your unfolded UVs, you need to export them so that you can draw a texture on them. You can do this by taking a snapshot of your UV layout.

To export a UV snapshot

1. Right-click the torso in the perspective view and select UV from the marking menu.

2. Drag-select all the UVs on the torso.

3. In the UV Texture Editor, use the Scale Tool and Move Tool to transform the mesh so that it fits inside the upper-right square of the UV Texture Editor.

   

4. Right-click the torso in the perspective view and select Object Mode.

5. Select the torso.

6. In the UV Texture Editor, select Polygons > UV Snapshot.

   The UV Snapshot options window appears.

7. Click the Browse button.

   The file browser appears.

8. Navigate to GettingStarted2015LessonData\UVMapping and enter the name torso_UVs.

9. Click Save.

10. Set Image Format to Maya IFF.

11. Click OK.

Maya creates a file named torso_UVs.iff in the Getting Started folder. If you open this file, you can see the exported UV mesh.

You can now open this file using an external image editor and paint your texture using the mesh as a guide.

NOTE:

If your image editing software does not support Maya .iff images, you can change the image format in the UV Snapshot options window and then export the file again.

[8] Unfolding with constraints

Sometimes you only need to unfold a UV mesh in one direction. This is especially useful when there is only a single seam.

To unfold the arms

1. Select the soldier’s left arm.

2. Select Create UVs > Planar Mapping.

3. Right-click the arm and select Assign Existing Material > checker_pattern.

   

   

4. Right-click the arm and select Edge from the marking menu.

5. Select the edges on the bottom of the arm at the center of the distortion just under the elbow.

   

6. In the UV Texture Editor, select Polygons > Cut UV Edges.

7. Right-click the arm and select UV from the marking menu.

8. Drag-select all the UVs on the arm and click the Rotate clockwise button (

   

   ).

   The UVs rotate so the arm in the UV Texture Editor is vertical.

   

9. Shift-select one UV at the top of the arm’s bicep and another UV at the tip of the soldier’s cuff.

   

   

10. Select Polygons > Unfold >☐.

    The Unfold UVs Options window appears.

11. Set Unfold constraint to Horizontal.

12. Click Apply and Close.

The UV mesh for the arm is unfolded evenly up and down. This is better than the UV mesh we would get if we unfolded in all directions.

Now you can output these UVs to a file.

To export the UV snapshot

1. Right-click the arm in the UV Texture Editor and select UV from the marking menu.

2. Drag-select all the UVs on the UV mesh.

3. Select the Scale Tool.

4. In the UV Texture Editor, scale the UV mesh so that it fits inside the upper-right square of the UV Texture Editor.

   This step is necessary because a UV snapshot only captures what is in the 1 x 1 UV texture space (the upper right corner).

5. Right-click the arm in the perspective view and select Object Mode.

6. Select the arm.

7. In the UV Texture Editor, select Polygons > UV Snapshot.

   The UV Snapshot options window appears.

8. Click the Browse button.

   A file browser appears.

9. Navigate to GettingStarted2015LessonData\UVMapping and enter the name left_arm_UVs.

10. Click Save.

11. Set Image Format to Maya IFF.

12. Click OK.

    Like the torso you did in the previous step, Maya outputs an .iff file containing the UV mesh. You can import this file into an image editor and use it as a template to create a texture.

Now repeat the entire procedure for the right arm. Note that you do not need to output the UVs for the right arm because it will use the same texture as the left arm.

Although you could handle the legs the same way you handled the arms (cutting them into two pieces), you can also treat the entire lower body as a single mesh. You can follow the same procedure as above, except for the following:

• Select the edges down the rear until directly underneath the groin then select the edges on the inside of each leg. Cut these UV edges.

  

• You do not need to pin any UVs for the pants (but you must select the pants as an object to unfold the UVs). Also, remember to turn off Pins UVs in the Unfold UVs Options window.

• Like the arms, unfold the UV mesh horizontaly.

As with the torso and arms, you can now output these UV meshes to an external file to paint a texture on them. For information about how to do this, see Outputting UVs.

[9] Sewing UV Edges

Depending on the mapping you start with, you may sometimes find that your UV mesh is broken up in ways that can ruin your final result. In these cases, you can manually sew UV edges back together.

To map the head to the UV space

1. Select the head and select Create UVs > Cylindrical Mapping.

   

   

2. Right-click the head and select Assign Existing Material > checker_pattern.

   

   Notice that because you started with a cylindrical mapping, the checker pattern on the sides of the head aren’t warped like in the previous examples. Unfortunately, if you tumble the camera you can see that the top of the head is now warped. In this particular case this is preferable and you will see the reason why later.

If you turn on texture border display by clicking the Texture Border Display icon (

)in the UV Texture Editor, and re-examine the top of the helmet, you can see that a few edges that are not on the line of symmetry are colored thick blue. This indicates that they are on the border of the UV mesh and will cause a seam. You can fix this by sewing these overlapping UV edges together.

To sew UV edges

1. Right-click the helmet and select Edge from the marking menu.

2. Shift-select the two thick blue edges at the top of the helmet that are not on the line of symmetry.NOTE:

   If none of the edges appear thick blue, click the Texture Border Display icon (

   

)in the UV Texture Editor

3. In the UV Texture Editor, select Polygons > Sew UV Edges.

   The thick blue edges change to match the other edges.

Notice that after sewing the UV edges together, the distortion has actually gotten worse. However, this is only temporary and is fixed when you perform the unfold.

To unfold the helmet’s UV mesh

1. In the UV Texture Editor, Right-click the face mesh and select UV from the marking menu.

2. Select the UVs down the center of the face starting from the tip of the helmet’s rim to the bottom of the neck.

   

3. Select Polygons > Unfold >☐.

   The Unfold UVs Options window appears.

4. Set Pin UVs to Pin selected UVs.

5. Click Apply and Close.

   The face unfolds evenly across the texture space.

   

[10] Smoothing/Relaxing a mesh interactively

Sometimes you only want to partially unfold a mesh. For this, you can use the UV Smooth tool to interactively unfold or relax the mesh.

To partially unfold the UV mesh

1. In the UV Texture Editor, select all the UVs.

2. Select Tool > Smooth UV Tool >☐.

   The Smooth UV Tool options window appears.

3. Select Edit > Reset Settings.

4. Set Space to UV Space.

5. Click Apply and Close.

   Two controls appear over the UV mesh called Unfold and Relax.

6. Click Unfold and drag the mouse to the right.

   The UV mesh unfolds as you drag the mouse to the right.

7. Continue to drag until the UV mesh roughly resembles the picture below.

   

   If you reach the edge of the screen you can release the mouse button, click the Unfold control and drag again.

[11] Fixing problem areas

You now have an unfolded UV mesh with no major overlapping faces. However, there are still a few minor problem areas where the mesh overlaps itself (particularly the eyes and mouth).

You can use the Smooth UV Tool to fix small imperfections in the shell with targeted unfolds or relax operations.

To fix the eyes

1. In the perspective view, right-click the soldier’s head and select Edge from the marking menu.

2. Shift-select the four closest edge loops that surround each eye. You can do this quickly by Shift+ double-clicking one edge in each loop.

3. In the UV Texture Editor, Ctrl+ right-click the UV mesh and select To UV from the marking menu.

   The edges selected around the eyes are converted to the UVs selected around the eyes.

   

4. Click the Smooth UV Tool icon (

   

   ).

5. Drag the Relax control to the right until the eyes appear round.

   As you drag the Relax control, the selected UVs relax until they are round.

   

Now you can fix the nose and mouth in a similar manner.

To fix the nose

1. Select a group of UVs on and around the nostrils.

   

2. Drag the Relax control to the right until the UVs stop moving.

   

To fix the mouth

1. In the perspective view, Right-click the head and select Edge from the marking menu.

2. Shift-select the 4 edge loops around the mouth. You can do this quickly by Shift+ double-clicking one edge in each loop.

   

3. In the UV Texture Editor, Ctrl+ right-click the UV mesh and select To UV from the marking menu.

   The edges selected around the mouth are converted to the UVs selected around the mouth.

   

4. Drag the Relax control to the right until the UVs stop moving.

   The mouth UVs even out into a circular shape.

   

5. Select all the UVs on the head.

6. Select the Scale Tool and scale the UVs so that they fit in the upper right corner of the UV space.

The UV mesh for the soldier’s head now has no UV faces overlapping. This allows you maximum control over what shows up in each portion of the head when you create the texture map for the soldier.

As with the rest of the body, you can now output these UV meshes to an external file to paint a texture on them. For information about how to do this, see Outputting UVs.

[12] Applying textures

Now that you’ve output all the UV meshes, you can import them into an external image editor to create a texture.

Once you’ve created associated texture files, you can apply them to your model. For the purposes of this tutorial, textures have been provided for you in the sourceimages folder.

To apply the texture for the torso

1. In the perspective view, Right-click the torso and select Assign New Material from the pop-up menu.

   The Assign New Material window appears.

   

2. Select Lambert.

   The soldier’s torso turns matte grey.

3. Open the Attribute Editor and select the lambert tab.

4. Change the name of the lambert material to Mat_Torso.

5. Click the box next to Color.

   The Create Render Node window appears.

   

6. Click File.

7. In the Attribute Editor, click the folder icon next to the Image Name field.

   A file browser appears.

8. Navigate to the GettingStarted2015LessonData\UVMapping\sourceimages folder, select soldier_torso.tif, then click Open.

   The body armor texture is applied to the soldier’s body. If the texture does not appear in the scene, press 6.

9. Select all the UVs and click the Smooth UV Tool icon (

   

   ). Slowly unfold the UVs until they roughly match the details of the texture as shown below.

   

   If the texture is not aligned or sized correctly you can adjust the UVs in the UV Texture Editor using the Toolbox.

10. Shift-click the torso and select Object Mode from the marking menu.

11. Select the torso in the perspective view.

12. In the Attribute Editor, navigate to the Mat_Torso tab,

13. Click the box next to Bump Mapping.

    The Create Render Node window appears.

14. Click File.

    A file tab appears in the Attribute Editor.

15. In the file tab, click the browse icon next to Image Name.

    A file browser appears.

16. Navigate to the GettingStarted2015LessonData\UVMapping\sourceimages folder, select soldier_torso_normals.tif, and click Open.

    Normal maps appear on the soldier’s chest. Normal maps give the flat portions of the texture the illusion of 3D bumps.

    

NOTE:You may need to perform a render of the scene view or switch to Renderer > High Quality Rendering or Renderer > Viewport 2.0 to visualize the normal maps.

Now you can repeat the process for the other body parts by applying the following textures:

NOTE:

When reusing a texture for a mirrored appendage (Right Arm or Right Foot), you must flip the UVs in the UV Texture Editor to fit the texture. You can do this by selecting all the UVs and clicking the Flip selected UVs in U Direction button (

) in the UV Texture Editor.

[13] Beyond the lesson

In this lesson you learned how to unfold a UV mesh so that you can create a texture for a complex organic mesh.

• You can divide a mesh into parts for texturing.

• You can create a planar mapping of UVs.

• You can apply a basic checker texture to find problem areas.

• You can cut UV edges in obscure areas to create a seam for unfolding.

• You can pin a UV and unfold a mesh in all directions or constrained to a single direction.

• You can partially unfold a UV mesh with the UV Smooth Tool.

• You can relax UVs to fix problem areas.

There are several techniques for texture mapping 3D surfaces depending on the surface type (NURBS, polygons, subdivision surfaces). Some techniques involve preparing the surfaces for texture mapping. For example, when texture mapping polygonal and subdivision surface types you need to understand how textures are applied using UV texture coordinates.

UV texture coordinates, or UVs as they are more commonly called, are two-dimensional coordinates that reside with the vertex component information for a 3D surface. UVs control the placement of a texture map on a 3D model by correlating the pixel position of the 2D texture map to the vertex positions on the model, so that the texture gets positioned (mapped) correctly.

For NURBS surfaces which have an inherent rectangular topology, the UV texture coordinates are implicit. That is, the UVs reside in the same location as the control vertices, so they have a natural correlation to a rectangular shaped texture map.

For polygonal and subdivision surface type models, which have an arbitrary surface topology, the UVs can be explicitly created and modified to suit the requirements of the texture map.

In this lesson you’ll learn the basic principles of UVs by applying (mapping) an existing image (texture) to a simple polygonal model and creating and modifying the UV texture coordinates so that the texture map appears correctly on the surface.

In this lesson you learn how to:

• Assign a 2D texture map to a polygonal model.

• Map UV texture coordinates (UVs) to a polygonal surface.

• Correlate the UVs between the scene view and the UV Texture Editor.

• Use the UV Texture Editor to visualize how the UV texture coordinates from a three-dimensional model relate to an assigned two-dimensional texture map.

• Determine basic UV layout requirements.

• Set preferences to let you visualize the texture borders in both the UV Texture Editor and the scene view to better understand how the texture map is placed on the polygonal model.

• Select and reposition UV texture coordinates within the UV Texture Editor using the transformation tools to make the UVs match a pre-defined texture map.

• Sew UV texture coordinates to existing UV shells.

[2] Creating a cracker box model

You begin the lesson by creating a model of a cracker box using a polygonal cube primitive. The dimensions you use for the cracker box are based on a texture map you apply to the model in this lesson.

To create a cracker box model using a cube primitive

1. Select Create > Polygon Primitives > Cube >☐.

2. In the Polygon Cube Options window, select Edit > Reset Settings, set the following options, and then click Create:

   • Width: 8

   • Height: 10

   • Depth: 3

   • Width divisions: 1

   • Height divisions: 1

   • Depth divisions: 1

   • Axis: Y

   • Create UVs: On

   • Normalize: Off

A cube primitive in the shape of a rectangular box appears in the scene view.

When the Create UVs option is on it ensures that the primitive object is created with a set of default UV texture coordinates. All polygon primitives in Maya provide an option for creating UV texture coordinates at the time of creation.

3. Using the Channel Box, set the Translate Y attribute to 5 so that the cracker box is repositioned to rest on the X axis.

4. Rename the pCube1 primitive to: cracker_box.

   

[3] Applying a texture map to a polygon mesh

In Maya, surfaces appear in a rendered image based on the shading materials you apply to them. The default shading material that gets assigned to surfaces provides basic attributes such as color, transparency, and incandescence.

Depending on your final image requirements, you can enhance the visual impact of an object by adding one or more texture maps to the assigned shading material. One basic texture map you can apply is a bitmap image also referred to as a file texture. In this lesson, you apply a texture map we’ve created for your use on the cracker box.

For more basic information on shading materials and texture maps see the Rendering chapter of this guide and the Maya Help.

To assign a shading material to the cracker box

1. In the scene view, select Shading > Smooth Shade All from the panel menu.

   This displays the cracker box with a default gray, smooth shading material, lit using default lighting. Turning on Smooth Shade All displays the assigned shading material you apply to the cracker box in the steps following.

   

2. In the scene view, right-click on any region of the cracker box and select Assign New Material from the pop-up menu.

   The Assign New Material window appears.

3. In the list of materials, select Lambert.

   A new lambert shading material is created and assigned to the cracker box. The Attribute Editor appears and displays the various attributes for the new lambert shading material in the lambert2 tab.

   The new lambert material is identical to the default gray material that was previously assigned to the cracker box. However, it’s always a good practice not to modify the default shading material in the scene. Instead, you should always create a new shading material and modify it to suit your requirements.

4. In Attribute Editor, click the lambert2 tab and double-click in the lambert2 box and rename the shading material box_material.

   

   Renaming the shading material lets you easily identify it later on when you need to edit it. Naming items uniquely in Maya is a useful habit.

5. In the Attribute Editor, move the Color slider fully to the right so that the color box appears white.

   

   The shading material assigned to the box model also updates in the scene view so it appears in a brighter tone.

6. Click the Map button located to the right of the Color slider.

   The Create Render Node window appears and lists the various texture options you can apply (or connect) to the color channel of the box material.

7. Click PSD File from the list of 2D Textures.

   

   Choosing this option specifies that you want to apply an Adobe® Photoshop® format file as a texture. A PSD format file lets you keep the various components of your texture map on multiple layers. This is useful when you need the ability to edit a component of the texture during production.

   The Attribute Editor updates to display the options for the PSD File texture.

   TIP:

   If the Attribute Editor suddenly appears empty, it indicates that no objects are selected in the scene. Simply select the box model again in the scene to display the attributes for the box.

8. Click the Browse button (folder icon) to the right of the Image Name attribute to specify the image file for the texture map.

   

   A browser window appears with the path set to the default project directory. By default, Maya looks for source images for texture maps in a sourceimages folder whenever the project folder is set. Maya can use file texture images from anywhere on your workstation or local network. For example, you can have images on a central disk drive that is shared among users in a production environment.

9. Select the image file named UVLesson.psd and click Open.

   This file can be found in the GettingStarted directory that you set as your Maya project:

   GettingStarted2015LessonData\UVMapping\sourceimages

   The image contains 2D artwork for the front, back, top, bottom, and sides of the cracker box, created in Adobe® Photoshop® (in .PSD format).

   

   A small preview of the image appears in the Texture Sample box in the Attribute Editor.

   When a texture is applied to a shading material, its attributes get added to the existing attributes for the shading material. That is, all of the existing shading attributes remain unchanged except for the attribute modified by the texture. In this case, the grey color is substituted by the image of the cracker box artwork.

10. In the scene view, select Shading > Hardware Texturing from the panel menu to display the texture map on the cracker box model.

    

    The texture map does not appear correctly on the cracker box model because the default UVs for the cube primitive don’t correlate to the texture map properly. The texture map was designed so that specific sides of the box receive specific regions of the image. Right now, the complete image is being placed on every side of the object.

    To correct this problem you must modify the default UV texture coordinates for the model so they match the layout of the texture image. To do this, you use the UV Texture Editor.

[4] Viewing UVs in the UV Texture Editor

The UV Texture Editor lets you view and interactively edit the UV texture coordinates for polygon and subdivision surface types. UVs appear laid flat within the UV Texture Editor’s 2D view. It also lets you display the 2D image for the texture map in relation to the UVs. These features are critical for accurate and efficient placement of texture maps on polygon and subdivision surface types.

In this lesson, your goal is to ensure that the shape and placement of the UVs match the image as it appears in the 2D view of the UV Texture Editor. This will ensure that the map appears correctly on the cracker box model in the 3D scene view.

To open the UV Texture Editor in a two pane layout

1. Right-click any of the Quick Layout buttons on the Toolbox to display the pop-up menu and select Persp/UV Texture Editor from the list.

   The panel layouts update to display the Perspective view in the left pane and the UV Texture Editor in the right pane simultaneously. (You can close the Attribute Editor if it is still displayed.)

   

   This two pane layout is helpful for two reasons:

   • It shows you how one item selected in the 3D view relates to the UVs displayed in the 2D view of the UV Texture Editor and vice versa, without having to open and close the views repeatedly.

   • When you edit UVs for a surface mesh in the UV Texture Editor, you can immediately see the effect of the texture map on the model in the 3D scene view.

UVs do not initially appear in the 2D view of the UV Texture Editor until you select an object or change the selection mode for an object in the scene view.

To view UVs in the UV Texture Editor

1. In the scene view, right-click any region of the cracker box model and select Object Mode from the marking menu.

2. Select the cracker box model.

3. In the UV Texture Editor, dolly the view outwards so you can see the UVs for the cracker box as shown below. (To dolly, press the Alt key and drag the mouse to the left while holding down the right button on your mouse.)

   The UV texture coordinates for the cracker box model appear in the 2D view of the UV Texture Editor as a flattened, two-dimensional representation. The UVs appear highlighted with lines connecting the UVs to indicate the region of the texture the UVs represent.

   The image you specified as the texture map for the box also appears in the 2D view of the UV Texture Editor in the upper right quadrant of the 2D cartesian graph called the UV image range or UV Texture Space. The coordinates for this quadrant range from 0,0 to 1,1 and represent the texture space for the surface. How the UVs appear in this quadrant in relation to the displayed image has a direct bearing on how the texture gets mapped onto the surface.

   TIP:

   If the texture map for the cracker box doesn’t appear in the 2D view, select Image > Update PSD Networks in the UV Texture Editor to refresh the 2D view of the UV Texture Editor. Update PSD Network is normally used to refresh a PSD texture in Maya after you have modified the PSD texture in Adobe® Photoshop®.

   

   In this example, the UVs for the cracker box appear like a box where all six sides have been cut open and then unfolded flat.

   The texture map does not appear correctly on the cracker box for a number of reasons:

   • The UVs for the cracker box extend well beyond the default 0 to 1 UV range for the texture map in the 2D view of the UV Texture Editor. As the texture map displays within the 0 to 1 range, the UVs should also be positioned to fit within the 0 to 1 UV range, in most cases. Otherwise, the texture map repeats on the surface mesh, as it does in this case.

   • The position of the UVs do not match the specific regions of the image we’ve provided for the texture map. The regions of the image show the front, back, top, bottom, and sides of the box. The UVs should specifically match these regions to display the texture correctly. UVs do not automatically align themselves to a texture, you must manually reposition them.

   • The shape of the UVs don’t match the aspect ratio of the cracker box model in the scene view: 10 (Height) X 8 (Width) X 3 (Depth). This is because the default UVs for a Maya cube primitive are created based on a predetermined default shape and do not get updated if the shape or scale of the primitive is modified later on.

There are a number of things you can do to correct these issues depending on the situation. For this lesson, you will correct the UV and texture map misalignment by doing the following:

• Map a new set of UVs for the cracker box model that better matches the individual faces of the cracker box. (While the existing UVs could be modified, you’ll learn how to create new UVs in this lesson that will better match the size and scale of the 3D model.)

• Ensure the new UVs fit within the 0 to 1 UV range in the UV Texture Editor.

• Reposition the UVs so that they correlate to specific locations on the 2D image using the UV Texture Editor. This will ensure that the various sides of the box receive the correct regions of the texture map.

[5] Mapping UV texture coordinates

It is often necessary to create new UVs for a surface mesh in order to texture map it correctly. These situations include:

• Texture mapping a surface that doesn’t have existing UVs.

  This can occur when you import 3D models from other software applications that don’t create UVs.

• When the UVs for a surface are badly jumbled or are missing some UVs.

  This can occur when a surface has been edited or modified in some way and it becomes hard to determine what UVs may be missing as a result.

• When you need a unique set of UVs for a particular purpose.

  For example, if you want to paint a texture map directly onto a 3D surface, you may want to map UVs that allow you to paint using the 3D paint tools in Maya. Alternatively, you may want to create a unique set of UVs specifically for baking textures or light maps.

Maya lets you create UVs for polygonal and subdivision surfaces using a process called projection mapping, also referred to as mapping UVs. Maya provides several projection mapping types that map what gets viewed by a particular projection to a flat 2D view that can be subsequently correlated to your texture map using the UV Texture Editor.

In this lesson, you use a feature called Automatic Mapping to create new UVs for the cracker box model. Automatic mapping lets you specify the number of planes that will be used for the UV projection.

Automatic mapping is normally used when mapping UVs that require multiple projections of organic shaped models as it has the advantage of producing UVs that are proportional in scale to the world space area of the mesh faces of the surface.

Automatic mapping is useful when your mapping requirements are for non-overlapping UVs which fit within the 0 to 1 texture space, but which do not have to be contiguous; for example, when using the 3D Paint tool, Maya® Paint Effects ^TM , Maya® Fur ^TM or Maya® Hair ^TM .

You use automatic mapping in this lesson because it can produce a UV projection from three planar directions simultaneously which makes it a good choice for the shape of the cracker box model. That is, you can map UVs for the front and back, top and bottom and the two sides in one operation. This projection type is referred to as a triplanar projection.

To map UVs using Automatic Mapping

1. In the perspective view, select the cracker box.

2. From the main menu, select Create UVs > Automatic Mapping >☐.

   The Automatic Mapping Options window appears.

3. In the Automatic Mapping Options window, select Edit > Reset settings, set the following options, and then click Project:

   • Planes: 3

   • Percentage Space: 2

Setting Planes to 3 creates UVs based on projections from three separate directions. Setting the Percentage Space option to 2 sets the size of the space that appears between each of the separate UV projections when they are laid out in the UV Texture Editor.

When the projection is complete the new projected UVs from the triplanar projection appear in the UV Texture Editor.

NOTE:

Whenever a UV projection is performed on a surface, any existing UVs for the surface get replaced by the UVs from the new projection. To avoid replacing existing UVs you can explicitly save the UVs in a UV set. For more information on UV Sets see the Modeling guide in the Maya Help.

4. In the UV Texture Editor, dolly the view so it shows only the 0 to 1 UV range area that displays the image for the texture map and the new UVs (as shown below).

5. In the UV Texture Editor, select Image > Dim Image.

   The intensity of the image map is reduced so you can view the UV borders on the projected UVs more easily. The new UVs appear in the UV Texture Editor as shown below.

   

   • The six rectangular UV shapes, referred to as UV shells or simply shells, now match the aspect ratio for each of the six sides of the cracker box better than the earlier UVs.

   • The UV shells fit within the 0 to 1 UV texture range. Automatic mapping fits the UVs to the 0 to 1 range by default.

The texture map still does not appear correctly on the cracker box because the UV shells need to be repositioned so they align with the corresponding components of the image map.

While the shape of each UV shell is now recognizable as being associated with the cracker box, it is not apparent which components in the UV Texture Editor correspond to a particular face on the cracker box.

In the next section you learn how to select and reposition the UV shells so they better match the image for the texture map.

[6] Working with UVs in the UV Texture Editor

When texture mapping a polygon or subdivision surface type model it is often necessary to modify the UV components for a model so they match the texture map. The UV Texture Editor provides many tools for working with UVs. In this section you learn how to:

• Select UVs from either the scene view or the UV Texture Editor and accurately correlate them. Selecting UV components is critical to modifying them accurately.

• Sew UV shells together to reduce the number of UV components you need to work with.

• Move and rotate UVs within the UV Texture Editor to make the UV shells align to the cracker box texture map.

Selecting UV components

You can select UV components from either the scene view or within the UV Texture Editor. Displaying both the 3D scene view and the 2D view of the UV Texture Editor lets you easily correlate which UV components are associated with a particular edge or vertex on the 3D model.

This is very helpful to understand the layout and orientation of your UV texture coordinates in relation to the image used for a texture map and how the map appears on the model in the 3D scene view.

To select UVs for a 3D model in the scene view

1. In the UV Texture Editor, select Image > Display Image to turn off the display of the texture image.

   Display Image works by turning the display of the assigned texture on or off in the 2D view of the UV Texture Editor. Turning the image off temporarily aids in viewing only the UV components. This will be useful in the steps that follow.

   

2. In the scene view, right-click on the cracker box model and select UV from the marking menu that appears.

3. In the scene view, select one UV on any corner of the cracker box.

   Selecting a UV is very similar to selecting a vertex on an object. That is, you select a point that resides in exactly the same position as the vertex. When you select a UV in the scene view, the corresponding UV is also selected in the UV Texture Editor.

   NOTE:

   If more than one UV gets selected in the UV Texture Editor when you select a UV in the scene view it indicates that multiple UV components share the same UV on the 3D model (similar to how polygon faces share common vertices). This is important to remember when you move one of these UV components in the UV Texture Editor and other UVs also move.

4. In the scene view, right-click on the cracker box model and select Edge from the marking menu that appears.

5. In the perspective view, select the top front edge of the cracker box.

   

   When you select this edge in the scene view, notice that two corresponding shell edges also get selected in the UV Texture Editor. This indicates the following:

   • The selected edge is shared by two faces; the front and the top.

   • Selecting the top front edge in the scene view identifies the corresponding front and top UV shells for the box. (Indicated by the selection in the UV Texture Editor.)

This is useful when you need to understand how the various UV shells relate to each other, especially when you have many UV shells for a model in the scene; for example, when you sew two UV shell edges together.

In the steps that follow you select edges in the UV Texture Editor so you can sew them together.

Sewing UVs

Sewing UV shells together merges the UV shells along a shared edge that you specify. Sewing UVs is useful for the following reasons:

• You can move and modify the UV shells as larger contiguous texture units. This makes it more efficient to match the UVs to the texture in many situations.

• Texture maps can appear more uniform across texture borders when the texture is applied to one or more sewn UV shells compared to many separate UV shells. Sewing shells together reduces the chance that an unwanted texture mismatch occurs along the texture edge.

To sew shell edges together in the UV Texture Editor

1. In the scene view, ensure that only the top front edge of the cracker box is still selected.

   When the top front edge is selected in the scene view, the top edge of one of the large UV shells is also selected as well as the left side of the middle UV shell in the top row of the UV Texture Editor. For the cracker box texture map, you need to sew these together so they correlate to the map correctly.

   

2. In the UV Texture Editor, select Polygons > Move and Sew UV Edges.

   The small rectangular UV shell is repositioned to match the top of the large UV shell and the two shells are combined into one. When you later select and move this sewn shell, it will move as one piece. When two UV shells are selected for sewing, the smallest UV shell is moved to the larger.

   

3. Repeat steps 1 and 2 for the remaining three edges on front face of the cracker box keeping in mind the following:

   • Select only one edge at a time in the scene view.

   • When you’ve completed the move and sew operation, your UV Texture Editor should show the front UV shell with the corresponding top, bottom, and side shells sewn to it. When fully complete, you will have only two UV shells to match to the texture image for the cracker box.

     

4. To display the texture borders for the two shells, select Texture Border Edges. (You can also launch this window by right-clicking the Toggle Texture Borders button

   

   on the UV Texture Editor’s toolbar.)

   In the UV Texture Editor, the texture borders for two UV shells now appear with a thicker line.

   

Displaying texture borders on the UV shells is useful for visualizing where the texture borders exist on the 3D model in the scene view. That is, any portion of the texture image that appears outside of the texture border will not appear on the surface. It is particularly useful for troubleshooting texture mismatches when they occur. Displaying the texture borders can also help to identify which UV shells are combined and which shells are not when you have many UV shells displayed in the UV Texture Editor.

If you want to be able to view areas where UV shells overlap in the UV Texture Editor select Image > Shade UVs. When Shade UVs is turned on any selected UV shells appear shaded in a semitransparent fashion. Areas where the shading appears more opaque indicate the regions of shell overlap.

In the steps that follow, you reposition the two UV shells in the UV Texture Editor so they coincide with the texture image.

Moving UV components

You manually reposition UV components in the UV Texture Editor using the tools within the Toolbox. To reposition an individual UV component you must first select it before selecting the Move Tool. To reposition an entire UV shell you must first select one individual UV from the shell it belongs to and then convert the selection to a shell before using the Move Tool.

To move UVs in the UV Texture Editor

1. In the UV Texture Editor, select Image > Display Image.

   The texture image displays in the 2D view of the UV Texture Editor dimmed, as before. You need the image displayed so you can accurately reposition the two UV shells. Dimming the image aids in seeing the selected UVs.

2. In the UV Texture Editor, right-click and select UV from the marking menu that appears.

3. In the UV Texture Editor, select one UV on the UV shell you sewed earlier in the lesson.

   The UV coordinate appears highlighted in the 2D view.

4. Convert the selection to a UV shell by pressing the Ctrl key and right-clicking in the 2D view of the UV Texture Editor. Choose To Shell from the marking menu that appears.

   The selection changes from a single selected UV to selecting the entire UV shell.

5. From the UV Texture Editor menu, select Tool > Move UV Shell Tool >☐.

6. In the Move UV Shell Tool options window, turn off the Prevent overlap option which prevents UV shells from being moved so they overlap and then select Apply and Close.

   The Move Tool manipulator icon appears over the selected UV shell.

7. Drag the green (Y-axis) and red (X-axis) Move Tool manipulator handles to reposition the UV shell so it matches the displayed texture image.

   

   The position of the texture updates on the cracker box model in the scene view as you do this.

8. Select one UV on the other remaining UV shell.

   The UV coordinate appears highlighted.

9. In the UV Texture Editor’s toolbar, click one of the Rotate UVs buttons

   

   

   to rotate the UV shell so it appears in the same orientation as the texture image. (Click the other Rotate UVs button to rotate it in the opposite direction.)

10. Confirm that the texture appears correctly on the cracker box model in the scene view by tumbling the scene so you can view the back of the box.TIP:

    If the texture appears upside down, you can continue to rotate it another 180 degrees. If the texture appears reversed, that is, the letters are backwards, you can correct this by selecting Polygons > Flip from the UV Texture Editor menu and choosing the appropriate option setting.

11. If it is not already selected, select Tool > Move UV Shell Tool from the UV Texture Editor menu.

    A move manipulator icon appears over the selected UV shell.

12. Drag the green (Y axis) and red (X axis) manipulator handles to reposition the UV shell so it matches the displayed texture image.

    The texture map should now appear correct on all sides of the cracker box when you’re finished.

    TIP:

    You can confirm that the UV shells are positioned accurately by dollying in closer on the 2D view of the UV Texture Editor. If a minor correction is required, simply select and move the UVs or move the entire UV shell.

    

    TIP:The exact UV boundaries can be viewed more clearly when the anti-aliasing for the texture image is temporarily turned off. To do this, select Image > Display Unfiltered to view the texture image without anti-aliasing.

    If you need to move a single UV so it precisely matches a particular location on the texture map you can turn on Pixel Snap (Image > Pixel Snap). When you select and move the UV using the Move Tool, it will reposition the UV coordinate based on pixel boundaries.

[7] Beyond the lesson

In this lesson you were introduced to a few of the basic techniques required to assign and accurately position texture maps on polygonal models using UV texture coordinates:

• UV coordinates are essential for applying and accurately positioning texture maps on polygonal and subdivision surfaces.

• UVs can be explicitly created for a surface mesh using a variety of UV mapping techniques. (Planar mapping, spherical mapping, cylindrical mapping, and Automatic mapping.)

• UVs are represented as 2D coordinates and are viewed and edited with respect to the 2D texture map using the UV Texture Editor. The UV Texture Editor provides many other tools for editing UVs.

• UVs are usually positioned to fit within the 0 to 1 UV coordinate space unless the texture map requirements are such that the map needs to repeat across the surface mesh.

• It is useful to display both the 3D scene view and the 2D UV Texture Editor simultaneously when texture mapping so that a correlation between the 3D model and 2D UV coordinates can be made.

• You can visualize texture borders using Texture Border Edges.

• You can view the regions where UVs overlap each other in the UV Texture Editor by selecting the UV shells and selecting Image > Shade UVs.

You can open the PSD file you used in this lesson using Adobe® Photoshop® to learn how layers were used for the texture map. You can edit one or more of the layers to experiment with how the texture can be modified. After you modify and save the file in Photoshop®, remember to select Image > Update PSD Network in the UV Texture Editor so the texture map gets updated on the model in the Maya scene.

If you would like to learn how to render an image of the cracker box model see the Rendering chapter of this guide as well as the Maya Help to learn more about lighting, shading, and rendering.

This lesson used a simple polygonal model to introduce the fundamental concepts. When you work with more complex polygonal and subdivision surface models, you can also:

• layout overlapping UV shells that occur as a result of UV projection mapping to ensure they fit within the 0 to 1 texture space using Edit UVs > Layout.

• maximize the use of texture space by forcing the UV borders to be mapped to the full area of the 0 to 1 UV texture range using Edit UVs > Map UV Border.

• align UVs to one another or snap them to the grid in the 2D view

• untangle a UV mesh that contains overlapping UVs using Edit UVs > Relax.

• modify a group of selected UVs using UV Lattice and UV Smudge tools.

In general, you should begin texturing a model only after the model is fully complete. Otherwise, changes to the model may affect the associated UV texture coordinates which in turn will affect how the texture appears on the model.

In this lesson you matched the UVs to an existing texture image. Many texture artists create good UV layouts for their models prior to creating the actual 2D images for their texture maps. This is done only after the model is fully complete.

You can export a bitmap image of the 2D view of the UV Texture Editor to use as a guide for painting a texture in your favorite image creation software. In the UV Texture Editor, select Polygons > UV Snapshot to export the image.

If you use Adobe® Photoshop® for image creation and editing you can create a UV snapshot in a .PSD file format that creates the UV image on a separate layer. To create the .PSD format file while working in the UV Texture Editor, select Image > Create PSD Network.

If you want to learn more about a particular tool or feature that was used in this lesson, please refer to the Maya Help.

Another method for creating NURBS surfaces is to loft a series of curves that define the cross section of your desired surface form. Lofting a surface works like stretching a skin over each of the cross sections to create the final surface.

In this lesson, you learn additional NURBS surfacing techniques by using the Loft tool to create the body of a salt shaker. You will also create the cap for the salt shaker by modifying the shape of a primitive sphere.

In this lesson you learn how to:

• Modify the outline of a circle primitive by editing the position of its CVs.

• Use the magnet snap feature.

• Loft cross section curves to create a NURBS surface using the Loft tool.

• Edit the form of an existing primitive object by moving its CVs.

• Parent one object to another using the Outliner.

[2] Creating profile curves for a surface

You begin the lesson by creating a pair of profile curves. You then create several copies of these curves to form the skeletal contours of the salt shaker’s surface.

To create profile curves for the salt shaker’s body

1. Make sure you’ve done the steps in Preparing for the lessons.

2. Select Create > NURBS Primitives > Circle >☐. In the options window, select Edit > Reset Settings, enter the following values, then click the Apply button:

   • Radius: 4

   • Number of Sections: 24

The Radius sets the size of the circle in grid units. A value of 4 creates a circle with enough size so that you can use the grid for convenient size comparison.

The Number of Sections sets the number of CVs in the circle. By using 24 CVs, you can create a circle with the subtle contours required in this lesson. Display the CVs of the circle to see the 24 CVs.

A circle is a curve that loops back on itself. The CVs work the same way as for any other curve. The more CVs you create for a curve or surface, the more detail you can give its shape.

The drawback to using many CVs is that you’ll have a harder time making smooth shape changes to broad regions. Also, more CVs means slower processing time as you work with the curve. It’s best to make curves with as few CVs as necessary. With experience, you’ll learn how many CVs to use in a situation.

3. Create another circle, this time with these options:

   • Radius: 2

   • Number of Sections: 24

This creates a smaller circle inside the first circle as shown below.

4. Change the scene view so you can see the circles from the top view.

   

5. Right-click the inner circle and select Control Vertex from the marking menu. Repeat for the outer circle.

6. Turn on Snap to Points (below the menu bar).

   

7. As shown in the following figure, move CVs from the outer circle to the corresponding inner circle positions. As you drag a CV near its destination, the Snap to Points mode causes the CV to jump to the exact CV position.

   

8. Turn off Snap to Points. Turn off the display of CVs for both circles by right-clicking on the circles and selecting Object Mode from the marking menu.

[3] Duplicating curves

In the next steps, you’ll create several copies of the previously created circles (also called curves) to form the skeletal contours of the salt shaker’s surface.

To duplicate curves for the lofted surface

1. Right-click the outer curve and choose Select from the marking menu.

2. Select Edit > Duplicate Special >☐.

3. In the Duplicate Special Options window, select Edit > Reset Settings, enter the following values:

   • Translate: 0, 3, 0

   • Scale: 0.93, 1, 0.93

   • Number of Copies: 4

4. Click Duplicate Special.

   This creates four copies of the original curve, each translated three units above the last, and each scaled smaller than the last.

   

5. Select the inner circle and then change the Translate values to 0, 13, 0 in the Channel Box. Increase its Scale attributes to 1.33, 1.33, 1.33.

6. With the inner circle still selected, use Edit > Duplicate Special >☐ with the following options:

   • Translate: 0 2 0

   • Scale: 1.05 1 1.05

   • Number of Copies: 3

This creates three copies of the circle, each translated two units above the last, and each bigger than the last.

[4] Lofting a surface

You’ve created a total of nine curves. In the next steps, you loft these curves into a surface that matches the contours of their perimeters. Above the midpoint of the surface, the shape will change from a flower-shaped perimeter to a circular perimeter.

To loft a surface for the salt shaker’s body

1. Starting from the bottom circle, and working towards the top, shift-select all the circles, one at a time.

   The order of selection is important when shift-selecting for a loft operation. You must start with the bottom flower-shaped circle and end with the top circular-shaped circle. Alternatively, you can drag a selection box around the circles. The surface to be lofted will be based on the selection order of the curves.

2. Select Surfaces > Loft.

   This creates the salt shaker’s body.

3. Name the surface shakerBody.

4. Press 5 to display the view with smooth shading.

   

   NOTE:

   Many of the surface creation tools also have the option of creating polygon or subdivision surface versions of a surface with the same input curves. You do this by setting the appropriate Output Geometry option for that particular surface tool.

[5] Modifying a primitive object

To create a simple cap for the salt shaker, you’ll create a sphere, alter its shape, and position it above the body.

To create and modify a sphere for the salt shaker’s cap

1. Select Create > NURBS Primitives > Sphere >☐. In the options window, select Edit > Reset Settings, and click the Create button. Maya puts the sphere at the origin, its display currently obstructed by the salt shaker body.

2. Name the sphere Cap.

3. Move the cap to the top of the body.

   

4. Scale the cap size so that its diameter fits snugly at the top of the body.

5. Adjust the cap’s position as desired.

6. In a side view, make sure that the cap is displayed as a wireframe.

7. Right-click on the Cap and choose Control Vertex from the marking menu.

8. Select the top row of CVs and drag them down until the top of the cap is flattened:

   

   Check that the bottom half of the cap isn’t poking through the visible surface of the body. You can scale the bottom CVs inward to avoid this problem.

[6] Using the Outliner to parent objects

The Outliner is an editor that is useful for quickly examining the structure and components of a scene. You can use the Outliner to quickly parent objects to create an object hierarchy.

To parent an object using the Outliner

1. From the main menu, select Window > Outliner.

   The Outliner window is displayed. A list of the scene’s components is listed in the Outliner.

2. In the Outliner, click on the word Cap to select it.

3. Parent the cap to the body by middle-mouse dragging Cap onto shakerBody1 in the Outliner.

   

   By parenting the objects, you can move, rotate, or scale the cap and the body as a single entity by selecting only the body.

   Notice that the salt shaker displays horizontal curves that wrap around the body. The curves are the original circles you used to loft the surface. Because these curves are part of the surface’s construction history, you can alter their shape if you decide you want to alter the shape of the body and the body will update based on the construction history.

   If you prefer not to see the curves in the scene view, select the curves and select Hide Selection. The curves won’t appear when you render an image of the scene. Maya displays only surfaces, not curves, in rendered images.

[7] Beyond the lesson

In this lesson you were introduced to the basic techniques related to lofting curves to create NURBS surfaces:

• You made a salt shaker with two surfaces: a body made from lofted curves and a cap made from an altered sphere. An advantage of creating a separate surface for the cap and base is that you can easily give each a different color or texture, for example, one chrome and the other marble. Another advantage of creating a separate cap is that you can animate the object separately. For example, you could choose to animate the cap unscrewing from the shakerBody.

• You used a Loft operation rather than a Revolve operation to create the body. The vertical corrugations on the surface would be impossible to create by revolving a curve.

• You can alter the position of the profile curves and the shape of the shaker will update because of the construction history. If you’re certain you won’t change the body’s shape by editing the shape of the lofted curves, you can delete the body’s construction history to quicken Maya’s processing of your interaction with the surface. (For a surface as simple as the salt shaker, deleting the history won’t boost processing much.)

• There are many other useful tools for creating and editing surfaces. For a glimpse of the possibilities, take a look at the Surfaces menu and the Edit NURBS menu.

If you want to learn more about a particular tool or feature that has been presented in this lesson, please refer to the Maya Help.

In addition to creating NURBS surfaces using curves, you can edit and sculpt surfaces and primitive objects in Maya using the Sculpt Geometry Tool.

The Sculpt Geometry Tool allows you to interactively push or pull on the surface regions to create areas that are embossed or in relief in relation to the surface.

In this lesson, you learn some of the basic concepts of these tools by sculpting a cartoon face and head from a NURBS primitive sphere using the Sculpt Geometry Tool.

In this lesson you learn:

• Basic sculpting operations (push, pull, smooth, relax and erase) with the Sculpt Geometry Tool.

• How the density of isoparametric lines affects the surface detail possible when sculpting.

• How to increase the surface subdivisions on a NURBS surface to aid with surface sculpting.

• How to change the brush radius for the Sculpt Geometry Tool.

• How Opacity and Max Displacement affect the sculpting operations.

• How to import geometry from a pre-existing file into your current scene.

[2] Preparing a surface for sculpting

Because a head is roughly spherical, you can create a primitive sphere as a quick starting point for creating a head and face.

To prepare a sphere for sculpting

1. Make sure you’ve done the steps in Preparing for the lessons.

2. Select Create > NURBS Primitives > Sphere >☐. In the options window, select Edit > Reset Settings, enter the following values, then click the Create button:

   • Radius: 6

   • Number of Sections: 30

   • Number of Spans: 30

     

The Radius sets the sphere’s size in grid units. A value of 6 creates a sphere big enough to use the grid for size comparison.

The Number of Sections sets the number of vertical curves, called isoparms, for the sphere. Isoparms show the outline of the surface shape. The more isoparms a surface has, the more CVs it has. (By default, CVs are not displayed.) More CVs means better precision as you edit a surface. The Number of Spans sets the number of horizontal isoparms.

The drawback to having too many CVs is that you’ll have a harder time making smooth shape changes to broad regions. Lots of CVs also means slower processing time as you work with the surface. It’s best to make surfaces with as few CVs as necessary.

We chose 30 Sections and Spans for this lesson because experience has shown that this allows adequate facial subtlety without slowing Maya operation on a workstation of modest processing power.

NOTE:

In wireframe display mode, if you select Display > NURBS > Fine or Medium, more isoparms appear than there are actual spans and sections. The surface is visually displayed with extra precision, but the extra isoparms have no CVs and cannot be edited.

3. Select the sphere and name it Egghead in the Channel Box.

4. Rotate the sphere 90 degrees on its side (Rotate Z: 90). This positions the sphere’s CVs well for modeling a simple head and face. You’ll learn why later in this lesson.

5. To give Egghead an oval shape, set the Scale X for the sphere to 1.3 or so. Optionally, you can move Egghead above the grid so the grid doesn’t interfere with your view of Egghead. Also, position the perspective view so the Z-axis of the View Axis points toward you.

   

Modifying the surface material for easier viewing

Because you will do subtle surface modeling in this lesson, it’s helpful to display Egghead with bright highlights so you can clearly see the effects of the changes you make. In the next steps, you’ll assign a Blinn material to Egghead to give its surface bright highlights. The steps have no explanations, as the shading subject matter is the focus of a later lesson.

To assign a Blinn surface material

1. With Egghead selected, select Shading > Smooth Shade All to display the surface with smooth shading.

2. Right-click Egghead and select Assign New Material.

3. Click Blinn in the Assign New Material window that appears.

   The Attribute Editor will immediately be displayed for the Blinn material.

4. In the Common Material Attributes section of the blinn tab, drag the Color attribute slider roughly 3/4 of the way to the right.

5. In the Specular Shading section, set Eccentricity to 0, and close the window.

   

[3] Basic sculpting techniques

In the next steps, you’ll become familiar with features of the Sculpt Geometry Tool. With this tool, you use your mouse or stylus to push, pull, or smooth a surface’s shape without selecting or displaying CVs. After you practice sculpting the surface, you’ll erase your practice strokes then begin sculpting Egghead’s features.

To practice sculpting using basic sculpting operations

1. With Egghead selected, select Edit NURBS > Sculpt Geometry Tool >☐. In the Tool Settings window, click Reset Tool, and make sure the Sculpt parameters are displayed.

   In the Sculpt Parameters section, there are a number of operations for sculpting a surface. Each affects the region of the surface where you drag (stroke) your mouse or stylus relative to the surface normals:

   

   • The Push operation depresses the surface in the region of the stroke.

   • The Pull operation raises the surface in the region of the stroke.

   • The Smooth operation diminishes bumps or ridges where you drag.

     Smoothing works by averaging the position of all features within the brush radius with all other nearby features.

   • The Relax operation paints over bumps to relax most of the out of place surface features.

     Unlike smoothing, Relax works by only averaging the largest surface anomalies so that the overall shape is maintained.

   • The Pinch operation pulls vertices inwards towards the center of the tool cursor.

     Pinching is useful for making existing creases more sharply defined.

   • The Erase operation eliminates the effects of the other five operations.

     The Erase operation works up to the last time you saved the scene or clicked the Update button to the right of Erase Surface.

2. Experiment with each of the six operations on the surface. Don’t be concerned with the results. Just become familiar with the response to your mouse strokes.

   By default, Push and Pull strokes deform the surface in a direction normal (perpendicular) to the surface. To create the resulting deformation more accurately, use Push and Pull strokes in a front, side, or top view while examining the results in a separate perspective view. Tumble the perspective view regularly for the best visual feedback.

   When you position the mouse pointer on the surface, it changes to a red sculpt icon that shows an abbreviation for the name of the operation you are performing. For instance, Ps stands for Push.

   The red icon also displays the radius of the region affected by the stroke. The Radius(U) value changes the radius.

3. Select the Erase operation and click the Flood button. This erases all your changes.

4. Select the Pull operation and enter a Radius(U) of 0.25, then drag between a pair of horizontal isoparms without crossing either.

   

   This has no effect because the stroke radius didn’t make contact with the CVs of either isoparm. Regardless of which operation you use, only CVs are affected by the strokes.

5. Change the Radius(U) to 2 and repeat the prior strokes.

   

   The strokes alter the surface because the radius overlaps the CVs. As this example shows, you need to make sure the radius is big enough to influence the desired CVs. It’s common to change the radius many times during a sculpting session.

   If you prefer to affect a small region without increasing the radius, you can add CVs to the region by inserting more isoparms. You’ll do this later in the lesson.

6. Flood-erase the changes to the surface as you did previously.

7. Select the Pull operation with a Radius(U) of 0.5. Drag along a vertical isoparm. For comparison, drag along a horizontal isoparm.

   

   NOTE:Turn off highlighting of the surface isoparms to make surface alterations easier to see. In the Preferences (Window > Setting/Preferences > Preferences) select the Display category and set Wireframe on Shaded to None.

   The vertical stroke creates a thinner ridge than the horizontal stroke because the density of vertical isoparms is greater. The number of underlying CVs and their positioning affects the outcome of your strokes.

   TIP:

   You can alternatively adjust the radius of the Sculpt Geometry Tool using a Hotkey. Move the tool over the object, press and hold the b Hotkey and drag left or right. The circle on the object with numerical radius value represents the size of your tool. Stroke on the object to try out a new size.

8. Flood-erase the changes to the surface as you did previously.

9. Rotate the camera view so the X axis of the View Axis points toward you. Draw a vertical Pull stroke again.

   

   As your stroke nears the center of Egghead, a kink occurs. It’s challenging to alter a surface symmetrically in a region where many isoparms converge at a single point, called a pole. Always consider the position of isoparms as you sculpt a surface. In general, sculpt where isoparms are evenly, regularly distributed.

10. Erase all changes again, then reposition the camera view so the Z-axis of the View Axis points toward you.TIP:

    If the Sculpt Geometry Tool is selected but not the surface you want to work on, right-click the surface and select Select from the marking menu.

[4] Additional sculpting techniques

Now that you’ve learned the basic features, you’ll learn other useful techniques before starting to model the facial features.

To practice additional sculpting techniques

1. In the Sculpt Parameter section of the Sculpt Geometry Tool, set Max Displacement to 2.

   

2. Draw a vertical Pull stroke.

3. Change the Max Displacement to 1.

4. Draw another vertical stroke nearby.

   The Max Displacement sets the maximum distance the surface’s CVs are pushed (or pulled) with a single stroke.

5. Erase the changes to the surface.

6. Set Max Displacement to 2.

7. Draw a vertical Pull stroke.

8. Set the Opacity from the default value of 1 to a value of 0.2.

9. Draw another vertical stroke nearby.

   One ridge is higher than the other. The Opacity value scales the influence of Max Displacement. For example, with an Opacity of 0.2, each stroke has only roughly 0.2 times the effect of the Max Displacement setting.

   It’s generally best to use a low Opacity value as you Push or Pull. You can increase the deformation gradually with multiple strokes.

   If you want to affect only a small region of a surface, use your mouse to click rather than stroke the region. If the Radius(U) and Opacity of the brush is small, you might need to click the nearest intersection point of two isoparms.

10. With Opacity set to 1, erase all changes to the surface again.TIP:Consider using an electronic tablet with pen stylus. A pen stylus is more natural for stroking surface changes as it feels like a pen. With a stylus, you can set an option that causes the Radius or Opacity to vary with stylus pressure. For example, you can have heavy strokes create a bigger Radius than light strokes.

    To do this, display the Stroke tab of the Sculpt Geometry Tool. For Stylus Pressure, select Opacity, Radius, or Both. Radius is a common choice. If you select Radius, the Radius(U) value on the Sculpt tab sets the maximum radius, while Radius(L) is the minimum. Explore various settings.

    If you use a mouse, set the Stylus Pressure to None. The Radius(U) sets a fixed radius. Radius(L) is ignored.

[5] Sculpting a nose

Now you’ll begin sculpting Egghead’s face, starting with a simple nose.

To sculpt a nose for the character

1. Position the perspective view so the Z-axis of the View Axis points toward you.

2. Reset the Sculpt Geometry tool.

3. Select the Pull operation and set the following options:

   Radius(U): 1 Opacity: 0.2

4. Select the Gaussian brush profile setting so your strokes have a soft, faded edge:

   

5. Above the midpoint of Egghead, stroke vertically downward to create the bridge of the nose—about the distance between two horizontal isoparms (see the following illustration). Use several strokes to build up the bridge. Create nostrils by stroking horizontally to the right of the tip of the nose a few times, then to the left of the tip a few times.

   To build up a small area, position the stroke icon there and click the mouse rather than drag. Tumble the view to examine your results after each stroke or click.

   

   If the strokes create a bumpy surface, turn on the Smooth operation and click Flood once or twice to smooth all strokes on the surface. Because Opacity is 0.2, the Smooth operation is subtle. Alternatively, you can smooth a selected region by stroking just that area. It’s common to smooth a surface regularly while using pull and push strokes.

   Because there are relatively few isoparms in the nose area, you can only create a simple nose that’s broad and rounded. If you want to create sharper features, for instance, depressed nostrils or sharp ridges, you’ll need to insert isoparms in the nose region. Sculpting a mouth describes how to insert isoparms.

[6] Sculpting eye sockets

Eye sockets provide an inset and backdrop for eyes.

To sculpt eye sockets for the character

1. Select the Push operation.

2. Leave other settings the same as for the nose.

3. To make a pair of identical eye sockets, display the Stroke settings in the Tool Settings window and turn on Reflection.

4. Set the Reflection Axis to X and then position the sculpt icon on Egghead.

   A pair of identical Push icons appears on Egghead.

5. Adjust the positioning as desired for the eye sockets. Click the mouse many times in the desired location.

   

   NOTE:

   If the Reflection setting does not push or pull in the same direction on either side of a NURBS surface you can adjust the Reference Vector to alter the direction of these operations. In the Sculpt Parameters section select UV Vector and turn on Enable UV Vector Adjustment. Click and drag the mouse left or right to adjust the direction of the U and V reference vectors.

[7] Sculpting eyebrows

Eyebrows help define how stern or pleasant a face appears.

To sculpt eyebrows for the character

1. Select the Pull operation. Use the same option settings as for the eye sockets, including Reflection.

   

2. Position the sculpt icons above the eyes and draw horizontal strokes. If necessary, click positions where you need to build up the eyebrows. Smooth the eyebrows as necessary.

[8] Sculpting a mouth

With the 30 Sections and 30 Spans specified for the original sphere in this lesson, the large space between isoparms in the mouth region makes it impossible to create a subtle shape for the lips.

To overcome this problem, you must insert isoparms in the mouth region before sculpting.

To insert additional isoparms

1. Right-click Egghead and select Isoparm from the marking menu.

2. From the Toolbox, choose the Select Tool.

   

3. Click the horizontal isoparm below the nose and shift-click the next two below it so they become yellow.

   

4. Select Edit NURBS > Insert Isoparms >☐. In the options window, turn on Between Selections, enter a value of 2 for # Isoparms to insert, then click Insert.

   

   This inserts two extra isoparms between each pair of selected isoparms, for a total of four extra isoparms. This provides enough CVs to create subtlety in the mouth.

   You might want to add vertical isoparms at the lips in a similar way. The extra isoparms would also be useful if you were to later enhance the shape of the nose. Insert isoparms only where needed. More isoparms means slower processing speed.

   In any case, do not change the number of isoparms by editing the original number of Sections and Spans in the makeNurbSphere history node. This will reshape your sculpted surface undesirably.

To sculpt a mouth for the character

1. Select the Sculpt Geometry Tool again.

2. Select the Push operation. Enter 0.2 for Radius(U). In the Stroke tab, make sure Reflection is turned on.

3. Starting at the center of the area appropriate for the indentation between the lips, stroke outward from the center. It’s best to start the stroke with the dual icons on top of one another (in other words, only one icon is displayed).

4. Select the Pull operation and set the Radius(U) to 0.3. Using a similar technique as for the prior step, stroke the upper lip. Repeat for the lower lip.

   

[9] Sculpting other facial features

You can now optionally add other facial features. Consider these tips:

• For facial features such as the chin, cheeks, and forehead, use a Radius(U) larger than 1 and start with a Maximum Displacement between 0.5 and 1.

• Insert isoparms wherever you want to add extra detail with the Sculpt Geometry Tool.

To create eyeballs for the sockets

1. Create a sphere (Create > NURBS Primitives > Sphere) and scale it as necessary to fit the socket.

2. Increate the eyeball's Scale X value to make it oblong.

3. With the sphere selected, press the Insert (Windows and Linux) or Home (Mac OS X) key so the sphere's pivot point is displayed.

   You need to set the pivot point for the eyeball at the origin before you can make a mirrored copy.

4. Press the X hotkey so the pivot snaps to the grid at 0, 0, 0.

5. Select Edit > Duplicate Special >☐.

6. In the Duplicate Special Options window set Scale to -1, 1, 1.

   This makes the new eyeball a mirrored duplicate of the original on the opposite side of Egghead's face.

7. Position the eyeballs in the sockets.

8. Select one eyeball, then shift-select Egghead and select Edit > Parent.

9. Repeat this process for the other eyeball.

To create simple, unadorned ears

1. Create, scale a squash a sphere.

2. Create ridges and valleys by using the Sculpt Geometry Tool.

3. Duplicate the ear by settings pivot point to the origin.

4. In the Duplicate Special Options window set Scale to -1, 1, 1.

5. Parent the ears to Egghead.

To import existing models into your scene:

1. If you saved the Eggholder scene in the prior lesson, you can import the egg holder into this Egghead scene, then position Egghead into the egg holder.

   To import the egg holder into the Egghead scene, use File > Import and select the name of the scene that contains Eggholder.

   Importing a scene imports all objects from that scene.

2. Increase (or decrease) the scale of the egg holder (or Egghead) as necessary for a snug fit.

[10] Beyond the lesson

In this lesson you were introduced to a few basic techniques related to sculpting surfaces:

• The Sculpt Geometry Tool is indispensable for quickly shaping a variety of surfaces. As you do your own projects, pay special attention to the position and density of isoparms before you begin sculpting.

• Isoparms converge at a single point (the pole). Pole regions of a primitive or surface are hard to sculpt so it’s best to avoid using the Sculpt Geometry Tool there. For example, when you created the original sphere in this lesson, you rotated it 90 degrees around its Z-axis. Because of the rotation, ears for the head would need to be modeled via a different technique (for example, you could model a pair of ears and parent them to the head).

• The density and orientation of isoparms on a surface affects the results with the Sculpt Geometry Tool. As you gain NURBS modeling experience, you’ll learn how to use the density and orientation of isoparms to your advantage.

• Primitive objects are useful objects for sculpting in many cases. After you create a primitive, you typically sculpt, scale, trim, or otherwise alter the object into a more complex shape. Though most primitives are surfaces rather than curves, they still derive their shape from curves.

  

  In general, a sphere makes a convenient foundation for creating a simple head, but it’s not ideal if you plan to animate an expressive, talking head. Many 3D artists start with a cylinder or a lofted surface. The procedures for doing this are more complex than starting with a sphere and are beyond the scope of this lesson.

A simple technique for creating NURBS surfaces is to create a curve for the profile of your desired form and then create a surface using one of the various NURBS surfacing tools available in Maya. In this lesson, you create an egg holder using NURBS curves and the Revolve Tool.

In this lesson you learn how to:

• Create a NURBS curve using the control vertices (CV) creation technique.

• Use the grid for visual reference when modeling.

• Determine the start and end points for a NURBS curve and its direction.

• Create a revolved NURBS surface using the Revolve tool.

• Change the display shading smoothness for a NURBS surface.

• Edit a NURBS surface by editing its initial profile curve when it is linked to the surface by construction history.

[2] Creating a profile curve

Revolve is a common modeling technique similar to shaping a vase on a spinning potter’s wheel. You must first create a profile curve in an orthographic view and use the Revolve Tool to create a surface.

To create a profile curve

1. Make sure you’ve done the steps in Preparing for the lessons.

2. Select Panels > Layouts > Four Panes so you can see multiple views of the scene.

3. Select Create > CV Curve Tool.

   This is the most commonly used tool for drawing curves.

4. In the front view, click the numbered positions as shown in the figure. Make sure the first and last positions are on the grid’s Y-axis (the thickest vertical line of the front view’s grid).

   

   Also, click three times in the same spot for positions 9, 10, and 11. This is necessary to create a sharp point or corner in the curve.

   To change the position of the most recent point clicked, you can middle-mouse drag it.

5. (Windows and Linux) After you click position 13, press Enter to complete the curve’s creation.

   (Mac OS X) Press Return to complete the curve’s creation.

   

   The points you clicked in the scene view become the control vertices (CVs) of the completed curve. CVs are points you manipulate to alter the shape of a curve (or surface). These points often lie away from the curve.

   It takes a little practice to be able to predict exactly where a curve will be positioned when you click CV positions with the CV Curve Tool. Once you’ve learned the technique, you’ll be able to create and edit curves with graceful symmetry. By default, you must click at least four points to create a curve with the CV Curve Tool.

   For some advanced operations in Maya, you need to know the meaning of the start of a curve and the curve direction. The start of a curve is the first CV you create when you draw the curve. It is indicated by a small hollow box at the first CV, visible as you create the curve. Curve direction is shown on the second CV after the start of the curve, indicated by a small u icon as you create the curve.

[3] Creating a revolve surface

With the Revolve surface tool, a curve is rotated about an axis to create a surface. The user can define the axis of revolution.

To create a revolve surface

1. With the curve selected, select Surfaces > Revolve. This creates the egg holder surface from the revolved profile curve. Examine the results in the perspective view.

   Maya does not delete the profile curve. In a subsequent step, you’ll edit the profile curve to alter the shape of the surface.

2. Select the surface and rename it Eggholder in the Channel Box.

3. With the pointer in the perspective view, press 5 (for Shading > Smooth Shade All).

   This displays the egg holder as a shaded surface rather than a wireframe in the perspective view.

   Press 1, 2, and 3 to switch between the different degrees of display smoothness. (These hotkeys correspond to the menu items under Display > NURBS menu item (Rough/Medium/Fine).

   The finer the smoothness, the greater the impact is on interactive performance when you work with complex models.

   The smoothness display only affects the scene view. Rendered images display with high quality smoothness regardless of this setting.

[4] Editing a revolve surface

After you create a surface from a revolved curve, you can reshape the original creation curve to reshape the surface. This is possible because Maya’s Construction History feature was turned on before you did the revolve operation.

Selecting the original creation curve can be challenging when it is situated amongst other existing curves and surfaces. The Outliner is an editor that is useful for quickly examining the structure and components of a scene. The Outliner is also useful for selecting objects in situations like this.

To edit a surface with construction history

1. Select Window > Outliner.

   The Outliner appears and displays a list of the items in the scene.

   

2. In the Outliner, select the curve you revolved (curve1) by clicking on its name in the list.

   The curve becomes highlighted in the scene views.

3. In the front view, right-click and select Control Vertex from the marking menu.

   The CVs for the curve appear.

4. Select and move one or more CVs to adjust the curve shape as desired.

   If you have trouble selecting one of the CVs in the front view, select it in the perspective view after dollying and tumbling the camera as necessary.

   This modifies the shape of the egg holder because it is linked to the shape of the curve by its construction history.

   

5. If desired, save the scene for future review.

6. Close the Outliner window.

[5] Beyond the lesson

In this lesson you were introduced to a few basic techniques related to NURBS modeling:

• Revolving a curve is the easiest way to create surfaces with radially symmetrical forms— wheels, vases, glasses, pillars, and so on.

• NURBS surfaces are webs of interconnected curves. The creation curves are used to create and subsequently modify the surfaces if required.

• Proficiency at drawing and editing curves is an important part of NURBS modeling.

• The grid is a useful aid for constructing and modifying curves.

Some additional points you should know are:

• You cannot render curves, so your work with them is always an adjunct to creating and editing surfaces.

• Besides moving a curve’s CVs to alter its shape, you can cut, attach, extend, close, and smooth curves.

• After you create a surface from a revolved curve, you can edit the surface at a component level by moving CVs or scaling groups of CVs on that surface to customize the shape of the surface. (You will need to turn off construction history in order to do this.)

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PART 1: Scene Setup & Image Planes

1.1 Start a New Scene

• Open Maya.

• Go to File ▸ New Scene.

1.2 Set Project Scale

• Open Windows ▸ Settings/Preferences ▸ Preferences.

• Under Settings, set:

  • Working Units → Linear: centimeters.

• Click Save.

1.3 Setup Viewports

• Press spacebar to open the Four Viewports: Top, Front, Side, Perspective.

• Use Panel menu > Orthographic > Front to open the Front View fully.

1.4 Import Image Planes

Front Image:

• Go to View (in Front view panel) ▸ Image Plane ▸ Import Image.

• Select the front reference image (e.g., spongebob_front.png).

Side Image:

• Switch to Side View → View ▸ Image Plane ▸ Import Image.

• Select the side reference image (e.g., spongebob_side.png).

1.5 Adjust Image Plane Position & Transparency

• Select each image plane → press Ctrl + A to open Attribute Editor.

• In imagePlaneShape tab:

  • Set Alpha Gain to 0.3 (makes image translucent).

  • Adjust Depth so the image appears behind the modeling grid (e.g., Depth = -10).

Tip: Use the Channel Box to position the image planes at correct locations:

• Front plane: X = 0, Z = -10.

• Side plane: X = -10, Z = 0.

1.6 Lock Reference Images

• Create a new layer in the Channel Box → Add image planes to this layer → click R (Reference) to lock them.

PART 2: Model SpongeBob's Body

2.1 Create a Polygon Cube

• Go to Create ▸ Polygon Primitives ▸ Cube.

• Set the cube size roughly:

  • Width: 10 cm

  • Height: 14 cm

  • Depth: 4 cm

• Press R to scale or use Channel Box.

2.2 Add Subdivisions

• With the cube selected:

  • In the Channel Box, set:

    • Subdivisions Width: 5

    • Subdivisions Height: 6

    • Subdivisions Depth: 3

2.3 Match the Front and Side View Silhouettes

• Use right-click ▸ Vertex, enter component mode.

• Use Move Tool (W) and Soft Selection (press B) to shape the cube:

  • Front view: match eyes, mouth, tie position.

  • Side view: shape the curve of his back and front body bulge.

PART 3: Model Legs, Arms, Eyes, and Clothes

3.1 Legs (Cylinders)

• Create ▸ Polygon Primitives ▸ Cylinder

  • Radius: 0.3

  • Height: 4–5

• Rotate and place at the bottom of SpongeBob's body.

• Use Insert Edge Loop to add 1–2 loops for slight bends.

3.2 Shoes (Boxes/Spheres)

• Create a sphere or cube for each shoe.

• Scale and shape them into simple cartoon shoes.

• Position and parent to each leg.

3.3 Arms (Cylinders)

• Same as legs, but thinner and shorter.

• Add edge loops to allow for bent elbow.

3.4 Hands (Simplified)

• Create a box or half-sphere for mitt-style hand.

• Add three stub fingers (small cylinders or extruded from palm).

PART 4: Model Eyes and Face Features

4.1 Eyes (Spheres)

• Create ▸ Polygon Primitives ▸ Sphere

  • Radius: ~1

• Place and duplicate for left and right eyes.

• Create smaller black flat disk for pupil using:

  • Polygon ▸ Cylinder → Scale in Z to flatten.

  • Place on eye surface.

4.2 Teeth

• Create two small boxes, place under upper lip area.

4.3 Nose and Cheeks

• Nose: Create a stretched sphere or extrude from face.

• Cheeks: Just extrude small areas and scale.

PART 5: Model Shirt, Pants, Tie

5.1 Shirt and Pants

• Add horizontal edge loop where shirt ends (use Insert Edge Loop).

• Select face ring below and Extrude outward slightly.

• Repeat for pants.

5.2 Belt

• Create a thin polygon strip (scaled cube or plane).

• Wrap around lower body.

• Model small belt holes using inset faces or cylinders.

5.3 Tie

• Use Polygon Plane or box.

• Shape into a diamond.

• Extrude a few sections for 3D look.

PART 6: Finalizing the Model

6.1 Combine All Pieces

• Select body, arms, legs, eyes, etc.

• Go to Mesh ▸ Combine.

• Select edges/vertices at junctions → Edit Mesh ▸ Merge to weld.

6.2 Add Thickness (if needed)

• For flat areas (shirt, tie), use Edit Mesh ▸ Extrude → Local Z to add thickness.

6.3 Smooth Preview

• Press 3 on the keyboard to preview the smoothed version.

• Use Insert Edge Loops to control smoothness (tight = sharp edge).

6.4 Hard/Soft Edges

• Select mesh → go to Mesh Display ▸ Soften/Harden Edges.

  • Use soft for curved areas (sponge body).

  • Use hard for flat edges (pants, shoes, belt).

6.5 Delete History

• Select all → Edit ▸ Delete by Type ▸ History.

6.6 Save Your Scene

• File ▸ Save Scene As → spongebob_model_v01.ma

Tools Used in This Tutorial

In this lesson you alter an existing polygonal head model into a goblin by sculpting the mesh with the transformation tools.

In this lesson you’ll be introduced to some of the polygon modeling options Maya provides by learning how to:

• Use reflection to perform symmetrical transformations to your model

• Use Soft Select to transform components with falloff

• Modify the falloff area and shape

• Create a custom falloff shape

• Select components using Marquee select and Drag select

• Use Camera based selection to limit the components you select

• Use the Split Edge Tool to separate edge rings

[2] Open the scene for the lesson

In this lesson, you’ll work with a scene that we created for your use. The scene contains a human head. In the remainder of the lesson, you’ll alter this into a goblin head.

To open the scene

1. Make sure you’ve done the steps in Preparing for the lesson.

2. Open the scene file named Poly_head.mb.

   This file can be found in the GettingStarted2015LessonData\PolygonModeling directory that you set as your Maya project.

   The scene contains a human head in a visible layer with a hat and glasses on hidden layers.

[3] Using Soft Select

You can use Soft Select to select components with falloff on a polygon or NURBS surface. Falloff is an area around the selected components that is affected by a transformation according to a weighting. Transforming components with falloff allows you to perform a smooth transformation over multiple components without having to adjust each component individually.

For this lesson you use Soft Select to make a number of adjustments to the head model, starting with the nose.

To stretch the nose

1. Select the Move Tool by clicking the icon on the Toolbox.

2. Right-click the head model and select Vertex from the marking menu.

   The vertices appear on the mesh.

3. Select a vertex on the tip of the nose.

   

4. Press the ‘b’ key.

   A circular colored area appears around the selected vertex.

   

   This colored area represents the falloff. Yellow represents areas of low falloff while black represents areas of high falloff. Areas with low falloff are affected more by transformations to selected components than areas of high falloff.

   Next you need to adjust the Falloff radius.

5. Press b and left mouse button, and drag to left or right.

   The falloff area grows and shrinks as you move the mouse. Adjust the size so that it encompasses as much of the nose as possible without touching the face.

   

6. Drag the Z-axis manipulator away from the face.

   As you drag the vertex away, the rest of the nose is smoothly stretched with it.

   

7. Select the Rotate Tool from the toolbox and, using the Z-axis manipulator, rotate the vertex down approximately 45 degrees.

   

8. Select the Move Tool again and drag the Y-axis manipulator down (it appears yellow when selected and green when unselected).

   This creates a bend in the nose.

   

9. Press b to turn off Soft Select.

[4] Selecting with Camera based selection

When selecting components on a model you often only want to select the components you can see and not the components behind them. You can use Camera based selection to limit your marquee select to only what the camera can see.

To pull out the chin

1. Double-click the Select Tool icon in the toolbox.

   The Tool Settings editor appears.

2. In the Common Selection Options section, underneath Marquee, turn on Camera based selection.

3. Right-click the head and select Vertex from the marking menu.

   The vertices appear on the mesh.

4. While looking at the front of the head, select the five vertices on the same vertex loop at the front of the chin by holding the left mouse button at one corner of them dragging a marquee selection over them.

   Only the five vertices in the front are selected.

   

5. Press ‘b’ to turn on Soft Select.

   A colored falloff appears on the surface of the face.

6. Hold the ‘b’ key and left mouse button, and drag to left or right to adjust the Falloff radius so that it encompasses only the chin.

7. Select the Move Tool and drag the chin down and away from the face so that it becomes longer and more angular.

   

Now you have a longer chin without affecting any of the geometry on the neck, which may have occurred accidentally if Camera based selection had been off.

[5] Sculpting with symmetry

To give the head a more goblin-like appearance, you need to make the cheeks and eyebrows more boney. However, to do this, you need to adjust both cheeks equally. You can do this with the transformation tools’ Reflection settings.

To modify both cheeks simultaneously

1. Double-click the Move Tool in the Toolbox.

2. In the Reflection section, turn on Reflection and set the Reflection axis to X.

3. Right-click the head and select Vertex from the marking menu.

   The vertices appear on the mesh.

4. With the camera positioned in front of the head, select a set of vertices on the left cheek.

   A colored falloff appears on both cheeks.

   

5. Pull the X-axis manipulator to the left so that the cheeks are pulled closer together.

   Both cheeks are transformed identically and appear more boney.

   

Now you can adjust the eyebrows to make the goblin angrier.

To rotate the eyebrows

1. Press ‘b’ to disable Soft Select.

2. Click the outermost vertex on the left eyebrow.

3. Press SHIFT key + double-click the innermost vertex on the left eyebrow.

   All the vertices on the same loop are selected between and including the two vertices.

   

   NOTE:

   The selection of vertices on the other side of the reflection seam does not appear complete after this step. This is normal and is rectified in step 4.

4. Press ‘b’ to enable Soft Select.

5. Hold ‘b’ and drag the mouse left and right to adjust the Falloff radius so that it only affects the eyebrow.

   

6. Click the Rotate Tool from the Toolbox.

7. Drag the dark blue rotate manipulator in the scene to rotate the eyebrows inward.

   

[6] Sculpting with Surface based falloff

The default setting in Maya uses a spherical volume to determine what components are contained in the Falloff radius. However, sometimes you need the Falloff radius to follow the contours of the surface. To do this, you must use Surface based falloff.

To make the ears pointy

1. Double-click the Move Tool in the Toolbox.

   The Tool Settings editor appears.

2. In the Soft Selection section, set the Falloff mode to Surface.

3. Tumble the model so that you have a clear view of the left ear.

4. Right-click the head and select Vertex from the marking menu.

   The vertices appear on the mesh.

5. Select a vertex on the tip of the ear.

6. Hold the ‘b’ key and drag the mouse left or right to adjust the Falloff radius so that it encompasses the top half of the ear.

   

7. Use the manipulators to pull the ear until it’s pointed.

   

   Surface based falloff ensures that only the ear is affected by your transformation. If you were using Volume based falloff, parts of the head would also be moved along with the ear.

8. Select the Scale Tool and scale the ears along the X-axis so they become thinner.

9. Select the Move Tool again and pull the pointy end of the ears away from the head.

   

[7] Selecting with Drag select

In addition to marquee selecting sets of components, you can also select them by dragging over them with the mouse. This is similar to the way that the Paint Selection Tool works.

To make the eyes sockets more pronounced

1. Double-click the Select Tool in the Toolbox.

   The Tool Settings editor appears.

2. In the Common Selection Options section, turn on Drag.

   The mouse cursor turns into a brush cursor.

3. Beneath the Drag option, turn on Camera based paint selection.

4. Right-click the head and select Vertex from the marking menu.

   The vertices appear on the mesh.

5. On one side of the mesh, drag the mouse around the eye socket, beneath the eyebrow until you’ve covered a small area around the eye.

   You may find it easier to temporarily disable Soft Select to get a better view of what you are selecting. You can quickly toggle Soft Select on and off by pressing the ‘b’ key on your keyboard.

   

6. With Soft Select on, hold the ‘b’ key and drag the mouse to resize the falloff area so it covers only the eye sockets.

7. Select the Move Tool in the Toolbox and pull the Z-axis manipulator toward the head.

   

   The eye sockets are pulled in so that both the eyebrow line, bridge of the nose, and cheeks are better accented.

8. Press the b key to turn off Soft Select.

9. Right-click the head and select Object from the marking menu.

10. Select the two eyes and move them back along the Z-axis so they fit into the eye sockets again.

    

[8] Adjusting the Seam tolerance

You can use the seam tolerance to fatten the nose at the end.

1. Right-click the head and select Vertex from the marking menu.

   The vertices appear on the mesh.

2. Select a vertex on the left side of the tip of the nose.

3. Press the ‘b’ key to turn Soft Select on.

4. Hold the ‘b’ key and move the mouse left or right to resize the Falloff radius so it only encompasses the tip of the nose.

5. Select the Move Tool by double-clicking it in the Toolbox.

6. In the Tool Settings Editor, in the Reflection Settings section, click the Reset button.

7. Set the Seam Tolerance to 5.

   The Seam Tolerance controls the falloff around the seam. By increasing the number, you ensure that the vertices at the tip of the nose spread evenly.

8. Move the vertex away from the reflection line along the X-axis to widen the end of the nose.

   

Now you can unhide the hat layer to finish off the goblin.

To unhide the hat

1. Open the Channel Box and click the first empty box in the hat layer. A V appears in the box when the layer is selected.

   

The hat appears in the scene.

[9] Beyond the lesson

In this lesson, you learned how to:

• Activate Soft Select and adjust the Falloff radius.

• Transform components with Soft Selection.

• Use Camera based selection.

• Select components using reflection.

• Use both surface based and volume based falloff.

• Use Drag select.

• Adjust the Seam tolerance.

There are some additional Soft Selection options which are not described in this lesson:

• You can change the shape of the falloff curve in the Soft Selection tool settings either by adjusting the Falloff curve graph or by selecting any of the Curve presets below it.

  

  You can also save a custom Falloff curve to the Curve presets. For more information, see Change the shape of the falloff area in the User Guide.