Shape key driver not working when driven by another object (using Flex Rig from CGcoo

I am using the Flex Rig from CGcookie

In the above picture, the blue “bone” which control the lower lip works fine when I move it around by pushing “G” on the keyboard. By “works fine” I mean it moves the lip as expected.
My plan is to control some of those face features using motion capture tracks. I have setup “Empties” which are animated by the motion capture tracks and they work correctly. When I make the above blue bone an offset child of one of these “Empties”, the bone moves as expected but now it has no effect on the lip …which is weird because if the control bone is being moved, the lip should also move.
Can someone explain what the problem is?

Do you have ‘Auto Run Python Scripts’ turned on ??

Like I said, it works manually.

Yes. as I said, it works when using the G key.

If you have made the bone a child of the empty, the “child” will have no transforms when the parent is moved. This is basic parent/child behavior. The shapekeys in the FlexRig will only fire when the local transforms of those controls are changed.

Change your setup so the bones copy the location, rotation and scale of the empties they should follow.

Good luck!

Hi Dan, I have tried using a Tranform modifier but it also did not “fire the shapekeys” when the Empty was moved.

My current work around was to convert the Track to F-curves on the Empty, then copy paste the animation tracks from the empty to the bones which control the shapekeys. That way the control bone gets an animation track which seems to be what it needs in this case.

Converting the track to F-curves is VERY slow, so I would still prefer my original idea to work in some future version of Blender perhaps.