Aras PranckevičiusAug 30, 2023

You'd think there's a million ready-to-use "sort some things, on the GPU" codes out there, but outside of CUDA there isn't all that much. The ones that work, that is.

So I spent way too much time debugging sorting of a bunch of points! As a side effect though, Unity HDRP GPU sorting utility got a fix pull request :) https://github.com/Unity-Technologies/Graphics/pull/7954

Improve robustness of GPUSort wrt out of bounds buffer reads/writes by aras-p · Pull Request #7954 · Unity-Technologies/Graphics

Purpose of this PR GPUSort utility (which seems to be used for the "software" Line Rendering system in HDRP) in some cases produces incorrect results, at least on Metal (most notably, when the size...

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Show threadAntoine WebanckAug 30, 2023
@aras hey, I recently reimplemented bitonic sort on GPU (Shadertoy); what kind of sort were you after?
Show threadAras PranckevičiusAug 30, 2023
@webanck "any", for starters. As can be seen from the github PR link, right now I'm using the (bitonic) sort from Unity's HDRP. I just had to fix it first, since it was producing incorrect results in some cases lol :)
Show threadSebastian Sylvan
@aras @webanck one thing that’s nice about odd even is that it never makes the sequence less sorted in the intermediate steps. So you can amortize the passes over multiple frames in particle systems. I guess if you tracked which step you were in for the bitonic sort you could render the reversed subsequences in reverse order to get the same effect for bitonic.
Aug 30, 2023 at 5:44pmWeb