http://developer.download.nvidia.com/presentations/2008/GDC/slides-nvidia_advanced_skin_173.mov
Pretty complex mathematics, but knowing you guys you won't mind. I wish we could do something like this with terrains in TG2, but this might be a TG3 wish...not complaining, of course. Just thinking it's cool.
interesting, though i nearly fell asleep watching/listening to it ::)