I have two bones for the upper arm, and two bones for the forearm. This is to assist in proper deformations when rotating the elbow and wrist, respectively. (ie: Using forward kinematics, if I want to twist the elbow, I simply twist just the 2nd bone in the upper arm; to twist the hand, I simply twist the 2nd bone in the forearm)
How do I setup Inverse Kinematics using these bones? I don't want the movement of the elbow pole target to rotate the 1st upper arm bone and ruin the shoulder deformation, and same goes for the forearm/wrist. I'm having trouble figuring out the rig setup.