Well, one thing that comes to mind (Poser 5, mind you) is the ummm... what's that thing called again. >_> The displacement map. Although I haven't tried it myself, I've heard that it actually makes things raise/lower without changing the actual model itself. It's the way it's rendered. Also, you could try some bump mapping. I don't know if any of this is helpful, but it's a start I guess.