Shadow volumes for vertex-shaded objects

Dear forum,

Assume that I’m drawing a mesh with various kinds of vertex shading (the specific example I have in mind is for skeleton animation of objects), and I want to construct a shadow volume for that object.

Does anyone have any tips on how to accomplish that? Since I don’t know the final vertex coordinates on the CPU, how would I even know which edges to project the shadow from?

See:

among others.