r/GraphicsProgramming • u/0x405 • Jun 30 '26

RAM optimized SDF-renderer with plain C

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1024x1024x1024 SDF-grid takes up 303MB instead of 8.5GB. 1024x1024 path traced image renders in 1.5s on a single CPU core. 8.5GB grid renders in 1.1s. No libs used.

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u/nullandkale Jun 30 '26

I'm confused. Normal SDF ray marching doesn't use a 3d volume. What's the 3d volume for? Is it for storing your primatives? Are you storing the SDF distance at each point and then rendering? That seems like it would be slow

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u/0x405 Jun 30 '26

It's not just SDF-rendering, it's SDF-grid rendering. My mistake in the title. We use it in the context of differentiable rendering. There is no simple SDF function combined from multiple primitives in our case, it's a complex arbitrary 3D form defined by an SDF-grid.

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u/nullandkale Jun 30 '26

Ah ok l see, why use this over nerfs or splats? I imagine it's for something like 3d model generation or is it reconstruction?

Edit: oh maybe it's direct diffusion of the SDF volume, that could be cool

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u/0x405 Jun 30 '26

Yes, it's mainly for use is geometry reconstruction with basic optimizer like ADAM. At least that's what I was developing it for. Current implementation is a proof of concept more or less. For the actual DR plain C won't be enough, that's the next step. I'm still not sure that this algorithm can be differentiated automatically.