iPhone and occlusion culling.

I want to implement occlusion culling on the iPhone. I am currently looking into the HOM algorithm. I am afraid that reading pixel color when creating the HOM tree will be to slow on the iPhone. What are you opinions about this? Can you suggest another algorithm that may be good on the iPhone. I am currently just using view frustum culling and openGL back face culling.


Edit: I found this tutorial. This is exactly what I want do do. Can someone tell me more about the convex hull. Do I have to compute it for each frame? Wouldn’t it be easier to have models with a precomputed 3D convex hull. How does this work in reality?