   Finding edge points
  Maybe the subject is not entirely right, what I exactly need to do is to find 2 vertices of any shape composited from 8 vertices(max. shape cube) and I need to decide 2 points I will convert by gluProject(). So then I will be able do to sw occlusion culling (eg decide if the object being render is entirely covered by occluder = object's LeftUpX > occluder's LeftUpX and object's RightDownX < occluder's RightDownX and same for Y). I hope you understand me, because I'm not able to explain it properly.Thx, Andrew[edited by - osh on February 16, 2004 10:03:55 AM]