as there is an open interface to the collision detector you can replace it by your own. I would recommend trying out either Swift (Lin-Canny) or Solid (GJK) http://www.win.tue.nl/~gino/solid/index.html http://www.cs.unc.edu/~geom/collide/packages.html kind regards, Erwin Coumans >Would it be possible to use I_Collide or RAPID (or other package) for >collision detection?