Yes, occlusion is done AFTER octree/bsp culling.
You do your culling then you end up with a list of entities which are visible/partially visible or occluded by other entities in the scene.
In Blitz we don't really go down to the triangle level when rendering so I think what we are after is an occlusion technique which is just for whole entitities/meshes.
I've yet to actually need an occlusion system like this though, since graphics cards are so fast these days the octree/bsp/portal culling is enough to get the polycount down to a reasonable level.
I don't think most of us actually need it...that doesn't make it any less interesting to talk about though =)
You do your culling then you end up with a list of entities which are visible/partially visible or occluded by other entities in the scene.
In Blitz we don't really go down to the triangle level when rendering so I think what we are after is an occlusion technique which is just for whole entitities/meshes.
I've yet to actually need an occlusion system like this though, since graphics cards are so fast these days the octree/bsp/portal culling is enough to get the polycount down to a reasonable level.
I don't think most of us actually need it...that doesn't make it any less interesting to talk about though =)