   decomposing 3D models
  Does anyone know of any algorithms that can decompose nonconvex 3D models (assuming there are no artefacts or holes and is proper manifold) into a set of convex  models.thanksShaobo   
  I don't think this is possible, at least not if you allow non-polygonal descriptions of your models. If you are only dealing with polyhedra, you may end up with a very large number of small pieces.What do you need this for?   ;  well, restricting it to polygonal model is fine. I am interested in testing a collision detection system where the models are formed from convex objects, for which the GJK algorithm can be applied.   ;  The esteemed John Ratcliff has done a good implementation that does this for physics purposes.  Not sure, but I think you can find it as part of his CreateDynamics package.http://www.amillionpixels.us/CreateDynamics_1.0.exeHe has a lot of other good code up there, if you get a kick out of it, consider donating through his http://www.amillionpixels.us site.