I'm fairly pleased with my terrain LOD and shading now overall, but I think the surface looks kind of flat; all I'm doing now is some simple normal mapping. I've been considering applying the relief mapping algorithm I use elsewhere, but it seems that would require huge numbers of texture fetches.
With the high-detail fractal surface I'm currently using, I'm already doing 33 texture fetches per pixel with the fractal algorithm alone (11 bands with a anti-repetition algorithm that requires 3 lookups per band), and I'm worried that multiplying this by a large number of search iterations (10 or so) for relief mapping it might choke the GPU.
At what point will I be texture-fetch limited? Do I have better options than simple normal mapping with a high-texture-fetch fractal noise-based surface?
