SplatField

A simple pure Rust 3D Gaussian Splatting viewer — under 1.3K lines of code.

demo.mp4

Built with egui, wgpu, and cubecl.

Built to learn the details of 3D Gaussian Splatting. Learned a lot from Brush.

Docs

Doc	Description
Pipeline	3DGS forward pipeline overview, data structures, and rendering stages
Projection	3D covariance, local affine approximation, and 2D covariance projection
Rasterization	Tile-based dispatch, per-pixel evaluation, and alpha compositing

Interactive Diagrams

Diagram	Description
Tile Intersection	Drag to reshape the Gaussian and see tile coverage change
Alpha Compositing	Drag splats, adjust opacity and depth order, inspect pixel blending

Architecture

6 GPU kernel passes per frame:

1. Project — 3D to 2D projection, covariance, SH color, tile intersections
2. Depth sort — radix sort by depth
3. Remap — apply depth ordering to intersection IDs
4. Tile sort — sort intersections by tile
5. Tile ranges — build per-tile [start, end) ranges
6. Rasterize — front-to-back alpha blend to RGBA8 bitmap

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