Drive Shape Keys based on the Angle between Two Bones?

Support Animation and Rigging
3

Hi @bandages

Thanks for the response.

RE: why you don’t want to just use rotational difference? Is it that you want to discard any roll? There are other ways to do that.
Because computing for their dot matrix is much more reliable than their rotation values.
The “angle between” is not dependent on rotation rather on the matrix.

For the problem on using just rotation, I enumerate the problem in this thread.

RE: It looks like you did not do that, at least not for A.
You are right! I mistakenly changed the col[1] to col[0].
It now works as expected!

Thanks! :slight_smile:

You can check the updated file here:
https://www.dropbox.com/s/9kpvgzcjixykity/blen51_drive_shape_keys_based_on_bone_angle02.blend?dl=0