Apply *Relative* Shape Key to another mesh? I haven't started yet, but I'm asking now in case it affects my workflow.

I plan to rig a male/female character, and use shape-keys to deal with the problem joints (shoulders/hips).

I understand that to copy a shape-key to another mesh, the topology has to be the same and that can be done. But the shape of the male/female shoulder is different.

Is it possible that the relative transformation of the male's shoulder shape-key could be applied to the female's shoulder? For example, a vertex in the male's shoulder is moved -2(x) via shape-key. Would the female's shoulder also move -2(x) from its unique location, or do shape-keys use absolute co-ordinates?
Shapekeys save relative movements. You can test this by adding a shapekey then altering the mesh and seeing how the shapekey effects the mesh.

A simple shapekey movement - up four across five



After moving the original corner the shapekey moves up four and across five from the new starting position.