Facepunch Ships Gaussian Splat Library for s&box

Facepunch has released an official Gaussian Splats library for s&box that renders them with optional scene relighting, and walk on them. The library came out of the studio’s May 2026 hackweek, where developer Carson implemented splat rendering and collision generation, and it is installable from the s&box package registry now (sbox.game/facepunch/gaussian_splats).

The rendering half loads .ply and .sog files (the library ships its own PlyReader and SogReader) and renders splats that can optionally be re-lit using the scene’s lighting, including receiving shadows in real time. Carson’s hackweek post shows a Movie Maker animation built in about an hour with a re-lit splat as the environment.

The GaussianSplatCollider component voxelizes splat positions into a watertight static collision mesh, with each splat contributing its opacity to the voxel it occupies. A cumulative occupancy threshold filters out stray low-opacity floaters, and an optional largest connected cluster pass guarantees only the main structure gets collision regardless of how much junk floats in empty space.

Because splats can produce thin shells full of holes, the collider then seals them with one of two fill modes. FloorFill for outdoor scenes, which fills every voxel column downward from its highest solid voxel to make terrain solid, and ExternalFill for interiors, which dilates the walls to bridge scan gaps and flood-fills inward from the bounding box so everything unreachable from outside becomes solid. This might sound familiar and the method actually does credit PlayCanvas’s SplatTransform approach.

s&box launched on April 28 as Facepunch’s successor to Garry’s Mod, a user generated content platform whose entire premise is players building playable worlds. Facepunch labels the library experimental, created in a short time and possibly unmaintained going forward, but it shipped under the official Facepunch account, has been updated since release, and points newcomers to superspl.at for commercially licensed splat files.

Gaming continues to get progressively more interested in the world of gaussian splatting. I have continued to hear rumors of larger and larger studios turning their attention to splats. Learn more about s&box here.