Technical Notes
A short summary of our analysis of the Lumarit shader source, which we study as a reference for Unbound Visual+. Light bounce stays on SSGI.
| Technique | What it does |
|---|---|
| Flood Fill block light | Colored torch and block light spreads through a 3D voxel grid around the camera. Walls block it and tinted materials color it. |
| SSGI | One diffuse light bounce from visible surfaces, using cosine-weighted sampling and screen-space ray marching. |
| Temporal accumulation and bilateral filter | Gathers samples across frames, then smooths noise while keeping edges between different surfaces. |
| Ambient and ground bounce | Sky ambient from an atmosphere LUT, plus an analytic ground bounce so undersides never turn fully black. |
| Ambient occlusion | GTAO by default, with SSRTAO as an alternative mode. |
| Reflections | Screen-space reflections with a GGX microfacet model for rough and glossy surfaces. |
| Shadows | PCSS soft shadows with colored shadows from translucent materials. |
| TAA | Temporal anti-aliasing for a stable image. |
Not included: full voxel path tracing. The voxel trace functions in that source are placeholders, and SSGI only uses what is visible on screen, so bounce light can change or fade when off-screen sources leave the view.
Planned for Unbound
- Flood Fill block lightingA camera-centered voxel volume with six-neighbor propagation, light colors taken from textures, and blocking materials.
- SSGI and temporal denoisingCosine-weighted sampling, first-hit ray marching, depth-validated history, and a bilateral filter.
- Ambient and shadowsAnalytic ground bounce as an ambient fallback, combined with colored PCSS shadows.