View Full Version : Rigging a Wheel

03 March 2006, 07:14 PM
Hi everyone.
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?

03 March 2006, 11:31 AM
Hmm, better post your expressions next time, makes sense for the people helping you. Im a bit busy right now, so I cant get into details, jsut the rough basics. Id build a joint lying on the rotation axis of your wheel and add another joint onto that. This is the joint that controls your wheel and can be rotated.

Now you got two ways to deal with your wheel:

First just create an expression that only links one translation value to one rotation value, something like joint.translateY = joint.rotateX * 360. Now your wheel rotates 360 degrees when your character moves one unit. When your character jumps up, the wheel wont move, only when he moves front or back.

The second way is to simply limit your joints rotation to one axis. this is doen the attribute editor. This is a rather rough approach and invites future errors, so Id prefer a good clean script.

Hpoe that helped, otherwise post your expression and a screenshot of your character to receive more detailed help.



CGTalk Moderation
03 March 2006, 11:31 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.