On the screen on the right with all the flow graph stuff, you spotlighted the one section that was for the neck. Can you give us a rundown of what these sections are?
TL;DRThe MotionBuilder control rig combines an FK skeleton (spine, limbs, fingers, neck and head) with a separate IK rig of spheres, and the two switch smoothly without snapping because the rigging is programmatic.
So this control rig in MotionBuilder, and this is why the control rig in MotionBuilder is so powerful, is it has an IK and an FK rig built into it. Everything that you see in yellow, it's pretty much this whole tree hierarchy, this is your FK skeleton. This is your spine. If you think about this, this is kind of like a person, right? Here's his hips, spine, shoulders, down into his hands. I usually color code these fingers so I know that they're fingers, so to speak. Here's his legs right over here. And then right over on this side is his neck and his head. We actually have two neck joints in our character. Over here in the red and blue spheres, I'm going to X-ray him so you can actually see what I'm looking at. So again, here's the FK. Now all the red and blue spheres, these are the IK. And these are kind of like two separate rigs that have a symbiotic relationship with each other. They work with each other really nicely and you can easily go back and forth between IK and FK. A lot of programs, a lot of rigs, you have IK snapping and they have to do all sorts of code and scripting in order to prevent that kind of snapping. But because this is all programmatic, it's all built into the rigging.