.KSPLAT File Format

Introduction

A .ksplat file holds a Gaussian splat scene for GaussianSplats3D, Mark Kellogg’s splat viewer for three.js. It is the viewer’s own in-memory splat buffer saved to disk, so it loads with almost no work: the viewer converts a 3D Gaussian Splatting PLY or a .splat file to it once, and later loads are quick.

The format has three compression levels. Level 0 keeps 32-bit floats; level 1 keeps positions as 16-bit offsets within small cubes called buckets, and the rest as half floats; level 2 also keeps the spherical harmonics in single bytes. Harmonics go up to degree 2.

Structure

The file is little-endian. The current version, 0.1, is laid out as follows.

The file has no signature. It is known by its extension and by a header whose first bytes are the version 0 and 1, and whose section count fits the file.

In this reference

• Headers – the 4096-byte file header, the compression levels and the 1024-byte section header
• Sections and splats – buckets, the splat record at each level, and how it becomes a Gaussian

Links