Lumen GI and Reflections feedback thread

Thanks for the demo

Is it much faster than non-stochastic mode? I think the idea is similar than stochastic shadows, better performance for small tradeoff in quality?

This was literally the first commit for this, I am sure there will be some improvements down the line.

This would mean 5.5 gets changes for higher quality (Hit GI) and better performance (stochastic lighting)