Hi I''m trying to perform collision detection in my game using polytopes method as given in /advanced/collide example with the sdk. If there are any guidelines that must be kept in mind while creating the collision mesh pro file for my ,say room.pro file. I''ve made a room in a ground & want to perform collision from both inside & outside against its walls. I then made a collision mesh, like cmesh.pro in the example. To me it seems that inspite of all the 6 segments being loaded in polytopes list, its only performing collision against only one wall. That too on an infinite plane, ie it collide even outside of the room in the same direction of the wall against which it is detecting collision. Yes I''m a newbie with a little experience on genesis 3d only. Thanks in advance for any help/suggestions. Vshal