I'm new to XSI coming from Maya and I don't quite understand the volume controls that come with the biped rig. It looks as if the nulls that are made are part of the enveloping group and therefore will control the mesh, but how do I use the volume spheres that are created? One of the other things that happens is that the null that is created at the back of the thigh that I assume is meant to control the skinning at the butt jumps up to the front of the thigh when I move the foot control up too high. I try to read through the docs, but it didn't give me a whole lot. XSI looks to be the animation godsend from what I've been able to do with it thus far, and all these attributes look as if they will take my skinning to another level if I can only figure them out. Any help or direction will be much appreciated!