I may not be able to do this directly but thought I'd check. I have a gameboard whose game pieces are just bluescreen talent on top of shaped spheres (bluescreen texture on top with plain sphere geometry for base). The base of the gamepiece is fine but I'm wondering if there is any easy way to give the top piece depth, so when the talent moves his arms the front and back of the cube will have his video footage but I'd like the sides to have depth. I thought I could just make a planar surface with the video mapped to it and duplicate it a bunch but I'm sure the render times and interactive times will increase when I do that, just looking for an easier way.
So you want it to look like the piece is a sort of gingerbread-man shape, right? Extruded to some depth perpendicular to the texture's plane? And as the video plays, you want the shape of that extrusion to change, to match the changing pose?
Tricky. I don't think there's a good, simple way of doing it. Hmm.
Well, the simplest way to get geometry from texture is to use displacement mapping. What about this: you take the alpha of the video sequence, and apply it as a displacement map to a plane. You'll end up with a plane with the shape of the talent extruded out of it. But set up a transparency ramp for the surface, so that the back half of it (where the extrusion emerges from the plane, and the plane itself) is invisible.
I think that would produce the effect you're after. But it might not animate as smoothly as you need it to; I'm not sure.
If I haven't explained it clearly enough, post again and I'll try to clarify.