Rigify generated rig, hand IK controller has unexpected rotation

Question

I am having the same exact issue as described here:

Rigify widgets generating in wrong position and won't rotate. I would comment but do not have enough reputation.

A three-fingered character with mis-rotation of the hand IK control. See the attached .blend file. I believe I have setup the metarig with the proper rolls, and changing the roll of the hand or palm bones in the metarig has no affect on the outcome in the generated rig. I believe I have also assigned the correct rig types to the first palm bone as well as each of the fingers. All other controllers/bones seem to generate correctly. I cannot seem to set roll manually in the generated rig either. Is there a workaround?

Answer 1

Solved with the help of CGDive! https://blender.stackexchange.com/users/25308/cgdive

The generated rig tries to correct the roll automatically by default, but this can be overwritten by selecting each upper_arm bone and in Bone Properties > Rigify Type > Rotation Axis selecting the rotation axis manually. If you have copied the roll orientations from the human metarig template, then this should be Z manual for the arms. This causes the hand IK control to be correctly oriented when generating the rig.