Does it seem that if the sample rate is low, it is not a good strategy to put the sample in the random position of sub-pixels? And if the sample rate is high it would get a better result than just putting the sample in the centers of sub-pixels...
nsp
At pretty much any sampling rate it is a good idea to do this kind of stratified sampling where you subdivide a pixel into equal regions and sample randomly in each region. The initial subdivision helps guard against bad random number pulls, which could lump samples in a single part of the pixel by chance, and the "jittering" within each subregion helps guard against aliasing which may occur at this finer level (e.g., imagine a high frequency checkerboard where sampling in the centers of each region pulls out only the whites and skips the blacks).
Does it seem that if the sample rate is low, it is not a good strategy to put the sample in the random position of sub-pixels? And if the sample rate is high it would get a better result than just putting the sample in the centers of sub-pixels...
At pretty much any sampling rate it is a good idea to do this kind of stratified sampling where you subdivide a pixel into equal regions and sample randomly in each region. The initial subdivision helps guard against bad random number pulls, which could lump samples in a single part of the pixel by chance, and the "jittering" within each subregion helps guard against aliasing which may occur at this finer level (e.g., imagine a high frequency checkerboard where sampling in the centers of each region pulls out only the whites and skips the blacks).