SplatTransform - 3D Gaussian Splat Converter

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SplatTransform is an open source CLI tool for converting and editing Gaussian splats. It can:

📥 Read PLY, Compressed PLY, SPLAT, KSPLAT, SPZ formats
📤 Write PLY, Compressed PLY, CSV, SOG and HTML viewer formats
🔗 Merge multiple splats
🔄 Apply transformations to input splats
🎛️ Filter out Gaussians or spherical harmonic bands

Installation

Install or update to the latest version:

npm install -g @playcanvas/splat-transform

Usage

splat-transform [GLOBAL]  <input.{ply|compressed.ply|splat|ksplat}> [ACTIONS]  ...  <output.{ply|compressed.ply|sog|meta.json|csv|html}> [ACTIONS]

Key points:

• Every time an *.ply* appears, it becomes the current working set; the following ACTIONS are applied in the order listed
• The last file on the command line is treated as the output; anything after it is interpreted as actions that modify the final result

Supported Formats

Format	Input	Output	Description
.ply	✅	✅	Standard PLY format
.compressed.ply	✅	✅	Compressed PLY format (auto-detected and decompressed on read)
.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)
.sog	❌	✅	Bundled super-compressed format (recommended)
meta.json	❌	✅	Unbundled super-compressed format (also outputs .webp images)
.csv	❌	✅	Comma-separated values spreadsheet
.html	❌	✅	Standalone HTML viewer app

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 (deg)
-s, --scale      x                      Uniformly scale splats by factor x
-n, --filterNaN                         Remove any Gaussian containing NaN/Inf
-c, --filterByValue name,cmp,value      Keep splats where <name> <cmp> <value>
                                        cmp ∈ {lt,lte,gt,gte,eq,neq}
-b, --filterBands  {0|1|2|3}            Strip spherical-harmonic bands > N
-P, --params name=value[,name=value...] Pass parameters to .mjs generator script

Global Options

-w, --overwrite                         Overwrite output file if it already exists
-h, --help                              Show help and exit
-v, --version                           Show version and exit
-g, --no-gpu                            Disable gpu when compressing spherical harmonics.
-i, --iterations  <number>              Specify the number of iterations when compressing spherical harmonics. More iterations generally lead to better results. Default is 10.
-p, --cameraPos                         Specify the viewer starting position. Default is 2,2,-2.
-e, --cameraTarget                      Specify the viewer starting target. Default is 0,0,0.

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 to HTML viewer with target and camera location
splat-transform -a 0,0,0 -e 0,0,10 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 --filterNaN output.ply

# Filter by opacity values (keep only splats with opacity > 0.5)
splat-transform input.ply -c opacity,gt,0.5 output.ply

# Strip spherical harmonic bands higher than 2
splat-transform input.ply --filterBands 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 -p 0,0,10 -e 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

Getting Help

# Show version
splat-transform --version

# Show help
splat-transform --help