A developer known as hh-hang has published 3DGS Weather, an open source browser project that adds rain, snow, lightning and puddle reflections to a gaussian splatting scene.
3DGS Weather loads the environment as a SOG splat file and pairs it with a hidden glTF collision mesh, which handles collision detection and depth occlusion. A walking character and a drivable vehicle move against that mesh, and the same geometry lets rain, snow and puddles sit correctly in front of and behind the splats.
The lighting reaches the splats as well. A Spark shader modifier in the source blends ambient light, a sun that tracks the time of day, vehicle headlights and up to four flood lights into the splat colors. Depth maps rendered from each headlight's and flood light's view of the collision mesh then block that light, so a headlight beam stops at a wall without the splats shadowing one another.
Puddles carry ripples and a planar reflection adapted from three.js's Reflector, and the character leaves imprints in settled snow. The rain, splash and puddle code is adapted from the GPL-3.0 demo-2023-rain-puddle repository by Faraz-Portfolio, ported from React components to a plain three.js update loop.
3DGS Weather is written in TypeScript with Vite and runs on three.js r186 and Spark, the renderer World Labs took to version 2.0 in April and updated to v2.2.0 in September. Character control comes from three-player-controller, a separate package by the same developer.
EMX added rain and snow to splat scenes in ANNX AI Editor v1.8.0 as a screen effect inside a fixed volume around the camera. In 3DGS Weather the weather is tied to scene geometry through the collision mesh, with snow accumulating on surfaces and puddles spread across the ground.
The project is available on GitHub under the GPL-3.0 license, with a live browser demo.
