Forum Discussion
Why must the warping for the optics be done in a pixel shade
Ok, so please forgive the n00b question, I haven't had a chance to take a good look at what the pixel shader is doing, but I have seen the thread about raytracing, where the author has factored the wa...
"guysherman" wrote:
Thanks, that's a very clear explanation, and I now understand why ray-tracing works, but standard GPU rasterisation doesn't.
It's a real shame that it doesn't, because modern hardware rasterization is extremely fast. The problem is that modern GPUs are all built with so many internal optimizations that rely on the rasterization of straight (not curved) triangles, and so even if you were to implement GPU rasterization via the compute shader it would end up being very slow (this paper from NVidia in 2011 cites a 2x-8x slowdown from not using the hardware in the way it was meant to be used). Graphics card vendors could change this in the future and add efficient curved hardware rasterization. The benefits of this would be higher framerates for Rift games, as well as antialiasing and rendering to the native framebuffer size. However, that seems far off right now - perhaps it'll happen as VR rises in popularity.