View Full Version : make a middle joint free to rotate

 zoc10 October 2005, 05:31 PMHi! I've got 3 joint and iwould like that the rotation of the second one doesn't influence the rotation of the other down the hierarchy. It would be possible? thanks!
Dichotomy
10 October 2005, 06:17 PM
there are a couple ways you can do this.
First: probably the easiest way is to parent joint 3 to joint 1. Then joint2's rotation will have no affect on it.
Second: if for some reason that isn't what you want, you could create another joint (we'll call it Joint2.5). Place joint2.5 right on top of joint2. Parent 2.5 to 2, then use a multiply/divide node to cancel out the rotation of joint2 (feed Rx,Ry,Rz into 1x,1y,1z of multNode, set 2x,2y,2z to -1, then feed the output into the Rx,Ry,Rz of joint2.5) That will cause joint2.5 to rotate negatively of joint2, cancelling out the rotation.

There are probably a million other ways to do it, but those are two options. Personally I think the first is your best option, I use it all the time in arms and stuff like that.

NolanSW
10 October 2005, 11:58 PM
Could use a little script I wrote that does this.

Script (http://snolan.net/melscripts/snInsertJoint.mel)

Just select a joint and run the script.

Select the joint you want to make independent and hit the button.

http://snolan.net/images/snInsetScreenShot.jpg

Cheers,
Sean

zoc
10 October 2005, 02:17 PM
thanks guyz...
Nolan your script is cool thanks. The button independent insert make the same thing of dichotomy's first method, wich i've used to solve my problem...
Bye bye

NolanSW
10 October 2005, 02:56 PM