   Can one do motion blur by temporal MSAA?
  1. I'm talking about real motion blur, with multiple samples per-frame2. By temporal MSAA I don't mean ATI's trick of jittering the sampling patternThe brute force temporal supersampling is basically rendering multiple times and combining with some filter to get one motion-blurred frame.I'm wondering whether the multisampling trick used to speed up spatial anti-aliasing could be used for temporal antialiasing (motion blur).I'm thinking it would be analogous to the spatial MSAA--you compute temporal coverage values (use per-vertex velocities) and appropriately take color samples that directionally blurs your polygon edges.  Of course you need directional texture filtering as well, and without hardware support you'd either manually sample or interpolate between appropriate LODs of textures prefiltered in several directions (let's call it directional multi-mip-map; seen this trick used in prefiltered cubemaps for anisotropic reflectances in a paper years ago, they lerp between the closest two blur directions).Despite no hardware support, couldn't something like this be faster than temporal supersampling?  Has someone tried something like this already?  Apologies if it's a really stupid idea, as is entirely possible before my cupajoe   
  I think you'll have a blast reading 3dfx's T-buffer specs / papers, check out the GL registry maybe?   ;Quote:Original post by Prune1. I'm talking about real motion blur, with multiple samples per-frameIf you're going to take multiple samples per frame, the extra efficiency of using MSAA hardware to assist in merging the samples is going to be barely noticed. It's like writing hand-tuned assembly for the inner loop of an O(N^n!) algorithm.Perhaps I haven't grasped the full intricacy of your proposal. If so I apologize. Keep in mind the only efficiency to be gained from MSAA is in the broadcast of one pixel shader output to many frame buffer (sub)pixels. The savings is in pixel shader evaluation. It isn't immediately obvious to me how this would make multiple temporal samples per frame a fast operation.   ;  I was not just talking about the additional optimization of using less coverage samples than color samples, i.e. CSAA.  What I was getting at is to try to use the idea of MSAA to not supersample where not needed--inside polygons are treated by texture filtering only.  Multiple samples are only used for polygon edges.   ;  MSAA does increase the sample count for the whole scene though. In 4x MSAA, insides of polys still write out 4 samples, and edges of polys write out up to 4 samples.   ;  My bad.  The fragment shader runs per pixel; only color/depth/stencil are supersampled.   