   Bsptrees and OctTrees
  1.What is better to rpg game:oct tree or bsp tree.Bsp trees substitute z-buffer but video card are much better than eg 6 years ago.Do you use bsp tree still? 
  I don''t know how bsp tree works, but i do know about octrees. If your world is very flat, then i think you would be better off with a quadtree rather than an octree (it works the same except its 2D only). ;  I know .Quadtree and Octtrees are very similar.Bsptree is really difficult to coding so somobody use still bsp?;  Bsp-trees is still very common for spatial partitioning of indoor enviroments. For outdoor scenes you are better off with a quad- or octtree. 