For example, I have a rigged hand. Each finger has several bones:
Now I want to create a "fist" bone, that controls all the fingers, so I can make the hand clench by moving one single bone, while keeping the ability to make finer adjustments on each finger. In other words, I want something like shape key, just not for the mesh, but for the other bones.
Is it possible?
There are several ways to do this. I'll describe two of the more common ones.
Add the bone.
Add a Copy Rotation constraint, in pose mode, to each of the finger bones you want to curl when making the fist.
Adjust the influence setting on each bone to get the curl you want.
create a new action in the dope sheet.
set a keyframe for each bone you want to curl with the bone in the open position.
move to a different frame.
set a keyframe for each bone you want to curl with the bone in the curled position.
edit the animation until it looks good.
set a fake user on the action, so that it is retained.
use the new bone as a controller to apply the action.
