Occlusion with octrees

Question

I just started learning opengl and writing a first person shooter but I'm getting horrible framerates when I draw 5000 cubes. So now I'm attempting to perform occlusion and culling using an octree. What I'm confused about is where to cast the rays from. Do I only cast them from the fustrum near plane? It seems like I would miss part of the fustrum that expands. Any help is appreciated.

Answer 1

If 5000 cubes already gives bad framerates, you should consider changing the way you render your cubes.

It's very unclear to us what you are drawing the cubes for. If they are static (ie. don't move), then its best to pack them all into a single vertex buffer. If the cubes are supposed to move, then you should go for instancing. If you're going for a landscape made of cubes like minecraft, then you should create vertex buffers but only put in the faces of cubes that are actually visible.

I'd like to help more, but I'm unsure what you're doing.