I'm rigging a human figure for the first time, and I've followed a tutorial that involves adding constrained auxiliary bones to a) stabilize the shoulder area and b) redistribute the rotation along the arm, so that when the palm of the hand is rotated up, the wrist doesn't pinch and collapse.
The problem is, when I rotate the parent bone of the model beyond 90 degrees from its original orientation (at least on the Y-axis), some of the constrained bones apparently turn into black holes and suck in nearby regions of the model.
I posted this on another forum, and people have suggested it has something to do with "pole vectors" and "quaternions vs. Euler rotation" and have pointed me to tutorials with IK. None of this helps--I just want to point out that there's NO IK on this model yet. The problem, as far as I can tell, is much more basic than that.
Why is this happening? What am I doing wrong? How do I fix it?