Culling and scene

Speaking of culling, I've finished frustum culling and rendering using an octree as spatial structure. I've began also working on occlusion culling, and found a very intersting paper:

Coherent Hierarchical Culling Revisited

You can download the paper from there. It seems a very good techniques that uses Hardware Occlusion Queries with many render-state friendly optimizations, and seems also a real improvement to the basic technique.
But before moving to occlusion culling, I'm studying the design of the scene management, so when I've done with it I can create a real scene to test the CHC++ and also some simpler techniques of occlusion culling (using occlusion planes/frustum entierely on CPU). I found very interesting the use of occlusion queries, but if the scene you are about to render uses heavly the GPU it can impact the performances too much.
With the advent of the multicore cpus the old-fashioned-cpu culling can be of great impact on the performances.
In the meantime, I'll attach two simple shots of some random-placed meshes (the same as the previous post) this time entirely culled and rendered:

The first is the scene seen from the camera, the second shows the frustum and the object rendered.