SplatTransform - 3D Gaussian Splat Converter
| User Guide | Blog | Forum |
SplatTransform is an open source CLI tool for converting and editing Gaussian splats. It can:
📥 Read PLY, Compressed PLY, SOG, SPLAT, KSPLAT, SPZ and LCC formats
📤 Write PLY, Compressed PLY, SOG, CSV, HTML Viewer and LOD (streaming) formats
🔗 Merge multiple splats
🔄 Apply transformations to input splats
🎛️ Filter out Gaussians or spherical harmonic bands
⚙️ Procedurally generate splats using JavaScript generators
Installation
Install or update to the latest version:
npm install -g @playcanvas/splat-transform
Usage
splat-transform [GLOBAL] input [ACTIONS] ... output [ACTIONS]
Key points:
- Input files become the working set; ACTIONS are applied in order
- The last file is the output; actions after it modify the final result
Supported Formats
| Format | Input | Output | Description |
|---|---|---|---|
.ply |
✅ | ✅ | Standard PLY format |
.sog |
✅ | ✅ | Bundled super-compressed format (recommended) |
meta.json |
✅ | ✅ | Unbundled super-compressed format (accompanied by .webp textures) |
.compressed.ply |
✅ | ✅ | Compressed PLY format (auto-detected and decompressed on read) |
.lcc |
✅ | ❌ | LCC file format (XGRIDS) |
.ksplat |
✅ | ❌ | Compressed splat format (mkkellogg format) |
.splat |
✅ | ❌ | Compressed splat format (antimatter15 format) |
.spz |
✅ | ❌ | Compressed splat format (Niantic format) |
.mjs |
✅ | ❌ | Generate a scene using an mjs script (Beta) |
.csv |
❌ | ✅ | Comma-separated values spreadsheet |
.html |
❌ | ✅ | HTML viewer app (single-page or unbundled) based on SOG |
Actions
Actions can be repeated and applied in any order:
-t, --translate <x,y,z> Translate splats by (x, y, z)
-r, --rotate <x,y,z> Rotate splats by Euler angles (x, y, z) in degrees
-s, --scale <factor> Uniformly scale splats by factor
-H, --filter-harmonics <0|1|2|3> Remove spherical harmonic bands > n
-N, --filter-nan Remove Gaussians with NaN or Inf values
-B, --filter-box <x,y,z,X,Y,Z> Remove Gaussians outside box (min, max corners)
-S, --filter-sphere <x,y,z,radius> Remove Gaussians outside sphere (center, radius)
-V, --filter-value <name,cmp,value> Keep splats where <name> <cmp> <value>
cmp ∈ {lt,lte,gt,gte,eq,neq}
-p, --params <key=val,...> Pass parameters to .mjs generator script
-l, --lod <n> Specify the level of detail of this model, n >= 0.
Global Options
-h, --help Show this help and exit
-v, --version Show version and exit
-q, --quiet Suppress non-error output
-w, --overwrite Overwrite output file if it exists
-i, --iterations <n> Iterations for SOG SH compression (more=better). Default: 10
-L, --list-gpus List all available GPU adapters and exit
-g, --gpu <n|cpu> Select device for SOG compression: GPU adapter index | 'cpu'
-E, --viewer-settings <settings.json> HTML viewer settings JSON file
-U, --unbundled Generate unbundled HTML viewer with separate files
-O, --lod-select <n,n,...> Comma-separated LOD levels to read from LCC input
-C, --lod-chunk-count <n> Approx number of Gaussians per LOD chunk in K. Default: 512
-X, --lod-chunk-extent <n> Approx size of an LOD chunk in world units (m). Default: 16
Examples
Basic Operations
# Simple format conversion splat-transform input.ply output.csv # Convert from .splat format splat-transform input.splat output.ply # Convert from .ksplat format splat-transform input.ksplat output.ply # Convert to compressed PLY splat-transform input.ply output.compressed.ply # Uncompress a compressed PLY back to standard PLY # (compressed .ply is detected automatically on read) splat-transform input.compressed.ply output.ply # Convert to SOG bundled format splat-transform input.ply output.sog # Convert to SOG unbundled format splat-transform input.ply output/meta.json # Convert from SOG (bundled) back to PLY splat-transform scene.sog restored.ply # Convert from SOG (unbundled folder) back to PLY splat-transform output/meta.json restored.ply # Convert to standalone HTML viewer (bundled, single file) splat-transform input.ply output.html # Convert to unbundled HTML viewer (separate CSS, JS, and SOG files) splat-transform -U input.ply output.html # Convert to HTML viewer with custom settings splat-transform -E settings.json input.ply output.html
Transformations
# Scale and translate splat-transform bunny.ply -s 0.5 -t 0,0,10 bunny_scaled.ply # Rotate by 90 degrees around Y axis splat-transform input.ply -r 0,90,0 output.ply # Chain multiple transformations splat-transform input.ply -s 2 -t 1,0,0 -r 0,0,45 output.ply
Filtering
# Remove entries containing NaN and Inf splat-transform input.ply --filter-nan output.ply # Filter by opacity values (keep only splats with opacity > 0.5) splat-transform input.ply -V opacity,gt,0.5 output.ply # Strip spherical harmonic bands higher than 2 splat-transform input.ply --filter-harmonics 2 output.ply
Advanced Usage
# Combine multiple files with different transforms splat-transform -w cloudA.ply -r 0,90,0 cloudB.ply -s 2 merged.compressed.ply # Apply final transformations to combined result splat-transform input1.ply input2.ply output.ply -t 0,0,10 -s 0.5
Generators (Beta)
Generator scripts can be used to synthesize gaussian splat data. See gen-grid.mjs for an example.
splat-transform gen-grid.mjs -p width=10,height=10,scale=10,color=0.1 scenes/grid.ply -w
Device Selection for SOG Compression
When compressing to SOG format, you can control which device (GPU or CPU) performs the compression:
# List available GPU adapters splat-transform --list-gpus # Let WebGPU automatically choose the best GPU (default behavior) splat-transform input.ply output.sog # Explicitly select a GPU adapter by index splat-transform -g 0 input.ply output.sog # Use first listed adapter splat-transform -g 1 input.ply output.sog # Use second listed adapter # Use CPU for compression instead (much slower but always available) splat-transform -g cpu input.ply output.sog
Note
When -g is not specified, WebGPU automatically selects the best available GPU. Use -L to list available adapters with their indices and names. The order and availability of adapters depends on your system and GPU drivers. Use -g <index> to select a specific adapter, or -g cpu to force CPU computation.
Warning
CPU compression can be significantly slower than GPU compression (often 5-10x slower). Use CPU mode only if GPU drivers are unavailable or problematic.
Getting Help
# Show version splat-transform --version # Show help splat-transform --help