   Polygon Clipping and contact points
  HiI'm implementing some rigid body physics in my simulator. I only use boxes at the moment, when there is a collision between two boxes i calculate first the support points and then the contact points. This works fine when there is a point-poly collision. But when i have polygon - polygon collision i need to do some polygon clipping to get the contact points. Now here is my problem i can't ge this working cos my support points never seem to be ordered anti-clockwise. So is there any way to get the contact points when there is a poly-poly collision when my vertexes are randomly ordered ?   