I have noticed that many people complain about the Microsoft''s X File exporter for 3ds max (XFileExp.dle). The main problem is that it crashes when using the Physique modifier. I found a solution at: http://www.mvps.org/vbdx/tutorials/compilex/index.html There is just a description of changes to make in the exporter''s source code (so it must be recompiled manually). I tested it using the SkinnedMesh sample program from DirectX SDK and it finally seems to work. I hope this will be useful.