   World collision geometry
  Hi,I'm working in a home-made game engine. Currently I'm developing the collision system. But I was wondering how to deal with the world geometry collisions. Because for dynamic objects, I create a bounding box as collision geometry from their geometry meshes. But for the world geometry I don't know.What are the main techniques to deal with world geometry? I was thinking in having two world geometries. One detailed (with a lot of triangles for rendering) and another simpler (only with a few triangles for collision). But I want to know if there's one way to create automatically a collision bounding volume as in the case of dynamic objects.Thanks.   
  I did this not that long ago. My methods weren't sound and perhaps a more experienced developer could offer any improvements.Yes have a lower res model for the collision system but also I used a binary tree and split the world up into cubes, copying any geometry from the model that resides in a cube.You then get the position of the thing you want to collide with the world and query it against you cube list. Is it in the upper or lower half? Left or right? Each time you do this your geometry is halved and you do this until you have a sensible number of faces in a cube which you can run through a for loop for a collision.This sort of system has loads of room for improvement such as balancing your binary tree. What if your world is very left hand heavy on geometry? You can split the divisions up so that a fairly even number of polygons reside in each half to speed it up.Also what do you do if a polygon is half in one cube and half in another? I just duplicated it which made mine heavy on memory but you can split it or do some cleaver stuff with pointers.But a binary tree is almost certainly what you are after.Andy   