3D Gaussian Splatting has revolutionized real-time volumetric rendering by replacing traditional textured polygonal meshes with millions of radiance-bearing ellipsoids. However, raw training checkpoints and point cloud exports from Nerfstudio, Postshot, and Inria are delivered as massive binary PLY files that can easily exceed 500 MB to 2 GB per scene.
To stream and render these scenes inside standard web browsers at 60 FPS, converting uncompressed PLY data into the compact .splat format is standard industry practice.
Why Convert PLY to Splat?
A standard 3D Gaussian PLY file stores spherical harmonics coefficients up to degree 3 ($16\times 3$ floats per vertex), covariance matrices, and normals—totaling over 200 bytes per Gaussian point. In contrast, the .splat specification packs each Gaussian into exactly 32 bytes:
[32-Byte Splat Layout]
├── Position: 3 x Float32 (12 Bytes: X, Y, Z)
├── Scale: 3 x Float32 (12 Bytes: S0, S1, S2)
├── Color: 4 x UInt8 (4 Bytes: R, G, B, Opacity)
└── Rotation: 4 x UInt8 (4 Bytes: Quaternion Qx, Qy, Qz, Qw)| Metric | Raw 3D Gaussian PLY | WebGL .splat | Efficiency Gain |
|---|---|---|---|
| Bytes per Splat | 236 Bytes | 32 Bytes | 86% Reduction |
| Typical 1M Scene | ~236 MB | ~32 MB | Instant browser streaming |
| GPU Texture Load | Requires complex parsing | Direct single-pass upload | Zero CPU decoding overhead |
| WebGL Compatibility | Requires custom loaders | Universal across Three.js & Babylon | Standardized shader access |
Conversion Steps with FreeConvert3D
- Upload File: Drag your
.plyfile directly into the 3D Gaussian converter above. Everything processes in local WebAssembly memory. - Review Splat Count: Check the total Gaussian count and memory bounds displayed in real time.
- Download .Splat: Click Convert & Download .SPLAT to export your production-ready splat file instantly.
