A Recursive Algorithm to Render Signed Distance Fields
127 points by surprisetalk
by userbinator
1 subcomments
Unsurprisingly, it turns out that other people had already thought of applying the multi-pass technique on GPU, but the idea is not very widely known.
The demoscene is particularly insular, but even within the field of computing in general it seems that there is not a lot of knowledge diffusion between all the different areas, leading to some reinventions (often with distinct terminology.)
by linolevan
0 subcomment
Played around with the code to implement a little bit of SIMD. Was able to squeeze out a decent improvement, ~250 fps avg, ~140 low, ~333 high (on an m4). Looks pretty straightforward to do threading with as well. Cool stuff! Could work to bring more gpu stuff back down to the cpu.
by refulgentis
2 subcomments
Tl;dr: SDFs are really slow but cool because they can compactly define complex stuff; demoscene uses it. Sort of the functional programming to trad renderings OOP. Would be cool if it was faster. Optimizing an algorithm for CPU rendering using recursive divide and conquer, 1 core with one object gets 50 fps. 100 fps if you lerp a 10x10 pixel patch instead of doing 1 pixel. Algorithm isn’t optimized, fully. Also, turns out the author’s idea is previously known but somewhat obscure, it is referred to as “cone marching”
by 01HNNWZ0MV43FF
1 subcomments
Holy crap! The demo is hitting 30 FPS from certain angles, on my decade-old CPU
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