CryEngine2 atmospheric approach on GPU

I ported their approach on GPU and update is fast ! A 6200 can update a 256x256 map with 64 samples 9-11 times per second. With a temporary texture, you can update small quads but it's so fast that it's useless. Of course, no APG/PCIe bandwith, no cpu needed.

I also tryed to map texture into a full dome where viewer is at Origin. Some work needed to be done on shader to handle this but at last there is artefacts caused by poor tesselation of dome (always 32 rows, 32 cols on screenshots) and the uniform distribution of samples cause by low resolution texture stretching (8x8, 32x32). Problems that do not exist when using original code from O'Neil 's GPU Gems II or with a higher resolution map.

Note : On CryEngine2 they seem to map texture on a low tesselate geodesic dome. I use Oneil optimisations (GPU Gems II) which is much simpler than crytek that uses Nishita with 2D table.