Rastergrid is back with more details for their OpenGL4.0 Mountains demo, this time time they update the occlusion culling algorithm to utilitize the Hierarchical-Z buffer technology in new OpenGL4.0 spec.
Occlusion culling is a visibility determination algorithm that is used to identify those objects that did reside in the view volume but still aren’t visible on the screen due to occlusion. That means they are hidden by such objects that reside closer to the camera.
via Hierarchical-Z map based occlusion culling « RasterGrid Blog.
