View Full Version : Matching LRA of animation controls to joint?

 CoolDuck12 December 2004, 09:52 PMHi, I've search everywhere on the net including the archives here but couldn't find an answer to my Q. I need to match up the local rotational axis of my animation control (lets say a FK shoulder) to that of the shoulder joint. Lets say the joints are already reorientated and rotateX is for bending sideways down for the shoulder joint, but the animation control (nurbs curve) is rotateZ. So how do I change the LRA of the animation control to match up the joint. The point is I need to use Connection editor for anim control>>joint connections. I've tried, orient constraining the anim control to the joint, yes that worked, but the problem is, when I freeze transform that curve, it snaps back to the world axis. Parenting the anim control to the joint and freeze transformation of the curve also worked, but that would make the anim control be in the hierarchy of the joints. I'd be very grateful if someone points me in the right direction, cause I need this for my rig. Thanks in advance!
Rudity
12 December 2004, 12:34 AM
create a group, point and orient constrain it to the joint(delete constraints after if you want). Parent the control under than group, freeze transforms on the control.

That will zero out the animation control, and have its axis facing the direction of the group above, which is the same orientation as the joint.

Think of the situation like this.
Every object has a grid that rotates with it, when you parent an object underneith another object, it uses the parents grid as the 0,0,0 now, instead of the default world 0,0,0,

Here's an example in maya.
Create two cubes, at 0,0,0. Have them different sizes.
Rotate the larger cube 45 degrees.
parent the smaller cube underneith the larger cube.
For it to keep its position, it has to rotate 45 degrees the other way.
So its now -45 degrees in rotation.
If you were to freeze transforms on the smaller cube now, its LRA would zero out to the parent.
So, its now the same LRA axis as the parent, and 0,0,0,.

Hope that made sense. I'm in a hurry.

CoolDuck
12 December 2004, 09:32 PM
Cool thanks a lot for your help, it worked! Clever trick man.

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