sorry to revive an old thread, but it doesn’t seem right to start a new one.
I’ve been playing with unified sampling in maya 2013 extension, doing all the optimizations that have been documented, and I see the theoretical benefits, but I’m not convinced it’s better in every case.
I don’t usually have scenes with heavy transparency or severe raytracing features other than shadows, relying more on SSS in medical animations making FG and GI less worthwhile. I don’t render DOF or motion blur directly in my renders and I know that’s one of the major benefits of unified sampling that I’m not using.
I agree that the edge quality is inferior to adaptive sampling for the same render time regardless of how I tweak it. Textures have a little more pop with unified sampling, but can also be a bit grainier.
I’m still finding that I get a far superior image to render with adaptive sampling at 2x the target resolution with AA -1 min, 1 max, .17 contrast threshold and a slightly higher than normal filter like gaussian 3.5 with SSS lightmaps clamped to the target resolution, then downsize the final frames to the target resolution. Depsite the AA settings being slightly noisy at 2x resolution and using way fewer AA samples, it looks fantastic when downsized to the desired resolution -much better than unified sampling at 1x with high quality AA.
Depending on the scene, those render settings take around the same time as a 1x resolution with adaptive AA set to 0 min, 3 max, and .08 contrast threshold at 2.5 gaussian filter.
For a comparison of 1x resolution depending on the scene, unified sampling seems to render slightly faster for roughly the same quality, but for my scenes, it still doesn’t compare to rendering at 2x resolution with far fewer samples and then downsizing the frames.
Also, you get to keep all the calculated pixels at the 2x higher resolution instead of all that sampling work being filtered down and averaged into fewer higher quality pixels at 1x resolution.
This is how I’m able to render at 2160p for roughly the same price of 1080p and yet the 2160p frames look fantastic in motion because the pixels are so small anyway, it’s difficult to see the extra AA noise from the lower sampling - especially if you use some slight film grain in post.
Anyway, just posting my findings…