Auto clavicle setup

Rigging
1

Hey guys,

I’ve been scouring the internet looking for a good tutorial on setting up an auto clavicle on a rig I’m working on but I can’t seem to find any. Does anybody know how this setup works? I’m having a bit of trouble because I have the IK/FK setup on my arms and I can’t figure out how to get everything to work together. Any help is greatly appreciated.

2

I should mention what I do understand. I know that the auto IK will only work with my Ik arm and I have an FK clavicle control that works with my FK joints. I need to know how to integrate the clavicle from there.

3

really depends on what kind of Auto clavicle you want. You can use SDKs, node based setups, expressions, etc. Are you using maya or max?

4

I’m using Maya. I am just looking for a good way to get the clavicle to rotate realistically when you move the hand above the shoulder and when the hand is moved to the front and back.

5

hmm. I wouldn’t base it off the hand. Base it off the elbow position. The hand can go above the shoulder without the shoulder going up. You can easily use SDKs, expressions, or even some kind of node based setup to get the auto clavicle.

6

Hmmm. Good point. I shall experiment from here. I was reading about a node based setup that uses an aim constraint to move the clavicle. I think I’ll begin experimenting with that.

7

yes that is certainly a way you could do it. I believe that is in the Jason Schleifer Rigging Bundle. He goes over using aim constraints to drive the shoulder. There’s also something in Rigging for Animation that uses a pretty complex but awesome setup where you get the UV position of the elbow and base it off that rather than attempting to do it off Euler Rotations.

8

Jasons bundle ‘Integrating Animation Rigs’ I think has a good example. We run a very similar thing, heavily tweaked but same idea.

You have a copy of the ik Arm, duplicate solver, duplicate joint chain, but you constrain the chains root to the chest so it has no dependency. You then have a single joint aiming to the center of this clavchain’s forearm, giving you the rotation you require, and no cycle dependancy on the normal IK arm.

From then you just need to drive the clav itself, maybe via a blend node or remap node so you can tweak when the clav moves based on the arms rotation… ie, the clav shouldn’t really move until the arm is horizontal ish…

9

[QUOTE=Bharris;4632]yes that is certainly a way you could do it. I believe that is in the Jason Schleifer Rigging Bundle. He goes over using aim constraints to drive the shoulder. There’s also something in Rigging for Animation that uses a pretty complex but awesome setup where you get the UV position of the elbow and base it off that rather than attempting to do it off Euler Rotations.[/QUOTE]

That sounds similar to what I’m using;

A nurbs sphere with a greyscale ramp on it parented to the shoulder.
A locator parented to the elbow.

A closestPointOnSurface node with the nurbs sphere connected to closestPointOnSurface .inputSurface and the locator connected to closestPointOnSurface .inPositon

[I]createNode closestPointOnSurface;
connectAttr -f “nurbsSphere.worldSpace[0]” “closestPointOnSurface .inputSurface”;
connectAttr -f “locator.worldPosition[0]” “closestPointOnSurface .inPosition”;

[/I]

Then you connect closestPointOnSurface.parameterU and closestPointOnSurface.parameterV to the U and V inputs of the ramp:

connectAttr -f “closestPointOnSurface.parameterU” “ramp.uCoord”;
connectAttr -f “closestPointOnSurface.posV_remapped” “ramp.vCoord”;

Then you can query the outColor of the ramp and use that to drive your clavicle system.

Matt.