Page 1003 - Kitab3DsMax

Chapter 39: Animating with CAT and Creating Crowds
Naming CAT bones
When bones are added to a CAT rig, they are automatically named using the text entered into the Name
field. The default name of the entire rig is taken from the name entered into the Name field when the CAT
Parent is selected, and names for each body part are associated with the various object parts such as RLeg
and LArm. Each bone within a chain is given a default number, so the upper arm object is labeled as 1 and
the lower arm is 2.
If you change the name field, all bone names that are affected by the name change are automatically
updated, so changing the Name field in the CAT Parent to Reuben automatically changes all bones to start
with this name. This makes keeping track of all the various bones much easier and intuitive. It also helps
when you start to animate the rig.
Tutorial: Building a custom CAT rig to match a skin mesh
For this example, we use the CAT tools to create a custom rig that matches a mesh skin. The chosen mesh
skin is none other than Marvin Moose.
To create a custom CAT rig, follow these steps:
1. Open the Marvin Moose.max file from the Chap 39 directory on the DVD. This file includes the
Marvin Moose skin mesh positioned at the origin.
2. Select and right-click the moose skin mesh object, and select the Object Properties option from
the quadmenu. Enable the See-Through and Freeze options in the Object Properties dialog box.
Tip
The keyboard shortcut for making an object see-through is Alt+X. n

3. Click the Helpers category, open the CAT Objects subcategory in the Create panel, click the CAT
Parent button, and drag in the viewport to create the object. Make the CAT Parent just big
enough to contain the moose’s feet.
4. With the CAT Parent object selected, open the Modify panel and click the Create Pelvis button.
Then select and resize the pelvis object and position it to match the skin mesh.
5. With the pelvis object selected, click the Add Leg button to create the left leg. Select and
rotate the ankle so the foot is flat against the ground. Scale the foot to roughly match the skin
mesh’s foot.
6. Select the pelvis, and click Add Leg to create the opposite leg; then click the Add Spine button
to create the spine and an object for the shoulders. Position and scale the shoulder hub object.
Select the shoulder hub object, and click the Add Arm button. Position the arm bones to match
the skin mesh.
7. Select the shoulder hub object, and click Add Arm to create the opposite arm; then click the Add
Spine button to create another spine and an object for the head. Select one of the new spine
bones, and change the name to Neck and the number of bones to 2. Then scale the head bone to
match the moose’s head and horns, and name the head bone Head.
Figure 39.8 shows the completed custom CAT rig ready to be skinned and animated.

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