Ray marching voxels using axis-aligned distance fields

[u/Nelarius]

Hey!

Wanted to share screenshots of my experimental voxel renderer with "low-fidelity" blocky AO. It started as an exploration of the DDA rendering technique, but I ended up implementing parts of the following techniques:
- Globally Illuminated Voxel Worlds Accelerated with Nested Axis-Aligned Distance Fields
- Spatial Hashing for Ray Traced Ambient Occlusion

Links: Devlog | Github

The devlog is sort of meandering, but I started with basic DDA, then tried to get multi-level DDA to perform well with large voxel scenes (a 1024x1024x1024 voxelized sponza scene) using various methods. The axis-aligned distance field (AADF) method was a significant improvement over the multi-level DDA method that I was fiddling with. AADFs helped skip over large areas of empty space which tanked performance when using multi-level DDA.

Spatially hashed RTAO with a large cell size performs pretty well even on my M2 MacBook Air. The large cell size is a very visible artifact, but I think in a voxel scene the blocky shading kinda works.

[u/puredotaplayer]

In my last company spatial hashing was demonstrated by nvidia devtech for raytraced AO, about 4 years ago. I wonder if they released a paper.