Generation of stratified cosine weighted samples on hemisphere I have had luck with cosine weighted hemisphere samples, and I know how to generate stratified uniform samples, but I wanted to experiment with combining the two. However, how do I correctly stratify the hemisphere when performing the cosine weighted sampling? Do I cosine-weight the stratification? How many rays do I cast in each stratum? 

My application is the collection of indirect samples in a lightmapper.
The classic method is to uniformly sample the disc at the base of your hemisphere and to project your samples upwards on the hemisphere (eg. compute z from x and y). This yields a cosine weighted distribution.

As the projection preserves stratification, you need only use stratified sampling of the disc to get a stratified cosine distribution.