Design 950 Winter 2003 with Brian Stone

Heather Caprette
Rigging the kinematic skeleton to the mocap data within Maya

Problem with Joints not following or moving along with their IK Handles that are point constrained to the motion capture locators.

1. Tried unparenting the neck Curve from Spine 7 (where legs come off) to see if that would free up the joints. They did move more into alignment with the Head of the animal by stretching bone Spine 7. The back of the spine still pointed off at a different direction from the head.
Also noticed that the curve is now not moving with the dog at all. The neck and head bones are in pink.

2. Next, I’ll try orient constraining the Hip root joint to the T1 (first thoracic vertebra) mocap marker.
Didn’t work.


3. Now, I’ll try saving the file as a different version and replacing the Spline IK with RP IK. Includes: Breaking constraint connections on all IK Handles. Freezing Transformations on all joints, reorienting every one of their local rotation axes, creating new RP_IK Handles, Re-Point Constraining IK Handles to Mocap Markers.
Result: The Hip Joint (a major Root Joint) is not traveling with the motion capture data and seems to be pulling all the other joints back with it.


4. I solved by Point Constraining the top “Reference1” node of the dog ik skeleton hierarchy to the Sacrum Motion Capture Marker. Now all the joints are following along with the motion capture markers.
New Problem: The upper back bones are bowing upward unnaturally. I’ll try taking out some bones to reduce this. See the spine bowing below. The straight line underneath the spine joints is the ik handle.

5. Reducing the number of bones in the neck and reestablishing the RP_IK sort of solved the problem. I still think the spine looks unnaturally stiff, but this seems to be the solution I'm going to have to stick with for now.

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