Driven Shapekeys and Constrained Bones Problem

Support Animation and Rigging
1

Hi all,

So I’m working on a character in blender 2.53 (for like ever) and I’m rigging the eyelids up. I determined the easiest way was to use shapekeys instead of bones to open and close the eyelids. So I have the shapekeys setup and driving them with controller bones, rotate the controller, the eyelid closes. Simple, no big deal, works great up to this point.

The bones that control the eyelid shapekeys does so by rotating the bones. I added extra bones to move up and down and constrained the eyelid shapekey control bones to them. At first I used a track-to constraint, now when I move the new bones up and down, the constrained bones rotate, as they should. The problem is, the bones that are rotated by constraints should engage the shapekeys but do not. If I turn the influence of the track-to constraint to 0, rotate the bone, the shapekey works fine, as before. Also tried an IK constraint, same results.

I can work around this, no big deal. But really, bones that control shapekeys can’t have constraints applied to them? Or am I doing something wrong??? Using 2.53 beta btw…

Thanks for any help,
Randy

2

This sounds like another example of an annoying feature of Blender;

When you move a bone by constraining it, it doesn’t really move, it only looks like it moves. Because of this, if you try to use that bone to drive something else, it won’t work, because it hasn’t really moved.

The correct solution would be for Blender to offer the option of using either the constrained or the unconstrained data as the driver. Unfortunately, it doesn’t, so you’re workaround is to drive the shapekeys direct from the constrained to bones.

HTH.

Matt