CGTalk - Expressions: why don't bones get all the rotation?

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GeoffClark

03-15-2006, 06:01 PM

Hello,
I'm working on a rig that uses control curve boxes to rotate joints. I have the head control box which rotates the head bone. it's a simple expression:

cl_headaJNT.rotateX = headCTRL.rotateX ;
cl_headaJNT.rotateY = headCTRL.rotateY ;
cl_headaJNT.rotateZ = headCTRL.rotateZ ;

but, when I rotate the headCTRL box, the head bone is rotating at a different, slower, rate. Why?
Anybody else fixed this problem?
I have tried adding a multiplier to the end of each line (* 11), which almost makes the two rotate at the same rate, but then the rotation manipulator is left behind, which is not good.

Thanks,
Geoff Clark

animationrigs

03-15-2006, 06:32 PM

Some things to check.
1. Is your control the same rotation order as your joint?
2. If your control is a transform and your joint is a joint, depending on how you setup your hierarchy the rotaitons won't correlate correctly. Especially if you joint is oriented. This is because of jointOrients not being factored into transforms.

hope that helps

GeoffClark

03-15-2006, 06:55 PM

Thank you for those things. I will check them. I made a decision about it: I thought, "if I'm just doing a one-to-one rotation, why use an expression? I just added the handle to the bone and offset it. I have a jaw rotation attribute which I migrated over to the headbone as well, then deleted the control curve.

many thanks!

geoff

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