I am rigging a character with a wheel for a foot. Right now I have a nice little expression that attached his wheel's rotation to his foot's translation, so I don't have to animate the wheel spinning as he rolls across the ground. However, here's my problem. If I want to animate him jumping or skidding (or anything where the wheel's rotation wouldn't correspond with the foot's transaltion), I can turn off that expression and hand-key the rotation. But then when I turn the expression back on, that wheel is gonna rotate reeaaalll fast to catch up with the value of the foot's translation. That make sense?
Any suggestions on how I can avoid that ugly little side effect? Any other expression I oughtta use in it's place?