Rigging Characters for Animation, Pt. 1, From New Riders | 10 | WebReference

Rigging Characters for Animation, Pt. 1, From New Riders | 10

'; figDoc.write(zhtm); figDoc.close(); } // modified 3.1.99 RWE v4.1 -->

Inside Maya: Rigging Characters for Animation. Pt. 1.

  1. Translate this duplicated Ik_Bind_Spine_ hierarchy's root node away from the spline IK hierarchy so that this whole situation isn't completely confusing when you try to select and rig up your joints in the 3D view window.

    You now want to create rotate plane IK handles at each joint of the new Ik_Bind_Spine_ hierarchy by starting with the root and then making an IK handle that is a single joint long using the IK Handle tool.

  2. Select the first joint and then the very next joint in the hierarchy going up the spine. Then start the next IK handle's base at the end location of the previous IK handle that was just created; continue this process until the end of the spine hierarchy is reached (see Figure 17.29). This procedure should exactly result in the same number of IK handles as there are joints in your hierarchy, minus one—the only joint that does not have an IK handle stuck directly on top of it should be the root (which will later be point-constrained).

    Figure 17.29
    Creating rotate plane IK handles at each joint of the new Ik_Bind_Spine_ hierarchy.

    Now you will perform a few steps to perfectly line up the rpIk spine with the spline IK spine.

  3. First, point-constrain each one of the rpIk handles to the corresponding joint that is part of the spline IK hierarchy. Then point-constrain the root of the Ik_Bind_Spine_ rpIk hierarchy directly to the root of the spline IK hierarchy (see Figures 17.30 and 17.31).

    Figure 17.30
    This image shows half of the IK handles as they are being point-constrained to the corresponding splineIk spine joints.

    Figure 17.31
    This image shows all of the IK handles after they have been point-constrained to the corresponding splineIk spine joints. The root of the Ik_Bind_Spine_ has been point-constrained to the root of the splineIk's spine joint root.

  4. Next, connect the scale attributes from each original joint in the spline IK hierarchy to the scale attributes of the corresponding duplicate joint in the Ik_Bind_Spine_ rpIk joint hierarchy.

    Because these two hierarchies are right on top of each other in the 3D view, the easiest way to select them is by looking at the two hierarchies side by side in the Hypergraph's Graph, Scene Graph mode. Then hit the Toggle Free Form Layout button and move the hierarchies side by side. By doing this, you can see exactly which nodes you need to connect to each other because each node in the hierarchy is right next to the corresponding one. Because the hierarchies are exactly the same, you simply need to open the Connection Editor, select a single spine joint first, and load it into the left side. Select the corresponding duplicate Ik_Bind_Spine_ joint second, and load it into the right side. Then quickly connect the scale attribute of the spine to the scale attribute of the corresponding IK_Bind_Spine.

  5. Next, group all the rpIk handles under one node by selecting them all and hitting Ctrl+g (see Figure 17.32).

    Figure 17.32
    Group all the rpIk handles under one node.

    You should now have three joint hierarchies that, for the most part, all move together and are controlled by the low-res control hierarchy. They have the capability of stretching and compressing, as well as rotating using an FK approach and translating using an IK approach. The only part missing is the FK capability to actually twist the low-res joint hierarchy and have the joints in the high-res joint hierarchy get the separate portions driven by the twist.

    To achieve the desired twisting capability, you will create locators to serve as weighed poleVector constraints for each rotate plane IK handle in the rpIk Ik_Bind_Spine_ hierarchy.

Created: March 11, 2003
Revised: November 7, 2003

URL: http://webreference.com/3d/insidemaya/1