BSPHitTest Ray to BSP geometry hittest Ideal to build FPS game, where weapons need to check a hit, in order to animate a missile etc...
 BSPNode BSPNode is a single node in a BSPTree
 BSPTree BSPTree is a scene graph structure that allows static scenes to be rendered without z-sorting or z-conflicts, and performs early culling to remove big parts of the geometry that don't need to be rendered.