Bone Location not updating driver


In case someone else runs into this. Very, very strange.

Setting keyframes and scrolling will make it work so it has to be a dependency issue.
I can live with it by keyframing the bones movement.

OK. I’m in the process of creating a driver for one of my bones in Blenrig based upon testing three position of the bones location matrix.

Simple enough. I wrote a python script to test various postions of the x, y and z bone location via a function call to the script. If the location of the bone fell within certain x, y, and z parameters, then the script updated a shape key driver on a mesh.

So during the test, I noticed that the shape key value does not update when you change the bones location unless you click update drivers on the mesh.

Is there a solution to this?

Here is a test file with the script “” and set up with a shape key driver on a cube.

When the bone moves in local x to say .8 the shape key should activate. It doesn’t unless you click update driver on the mesh. Am I missing something?

Any ideas why this won’t update by just moving the bone?testinglbonelocationscript.blend (446 KB)