ply2splat

A Rust crate and CLI tool for converting Gaussian Splatting .ply files to the .splat format.

Available on crates.io for Rust, PyPI for Python, and npm for JavaScript/TypeScript (Node.js & Web).

Workspace Architecture

This repository is organized as a Cargo workspace:

.
├── crates/
│   ├── ply2splat/         # Core library and CLI tool
│   ├── ply2splat-napi/    # Node.js/WASI bindings via NAPI-RS (@ply2splat/native)
│   ├── ply2splat-python/  # Python bindings via PyO3
│   └── ply2splat-wasm/    # Low-level WASM bindings (wasm-bindgen)

Features

• High Performance: Utilizes parallel processing (via rayon) for conversion and sorting.
• Fast I/O: Uses zero-copy serialization and large buffers for maximum throughput.
• Correctness: Implements the standard conversion logic including Spherical Harmonics (SH) to color conversion and geometric transformations.
• Python Bindings: Use the library directly from Python via PyO3.
• Node.js & Web Support: High-performance bindings for Node.js (Native) and Web (WASI) via @ply2splat/native.

Installation

Rust Crate

Add ply2splat to your Cargo.toml:

[dependencies]
ply2splat = "0.5"

CLI

Install the CLI tool directly from crates.io:

cargo install ply2splat

Or build from source:

git clone https://github.com/bastikohn/ply2splat.git
cd ply2splat
cargo build --release

The binary will be available at target/release/ply2splat.

Python Package

Install from PyPI using uv:

uv pip install ply2splat

Or install from source:

git clone https://github.com/bastikohn/ply2splat.git
cd ply2splat
uv pip install .

npm Package (Node.js & Web)

Install @ply2splat/native from npm:

npm install @ply2splat/native

This package provides high-performance native bindings for Node.js and falls back to WASM/WASI for supported environments.

Usage

CLI

Standard Installation (Rust)

ply2splat --input input.ply --output output.splat

Run via uvx (Python)

If you have uv installed, you can run the CLI directly without explicit installation:

uvx ply2splat --input input.ply --output output.splat

Run via Nix

If you have Nix installed:

nix run github:bastikohn/ply2splat -- --input input.ply --output output.splat

Native CLI via Node.js

You can also run the high-performance Rust CLI directly via Node.js without installing Rust or compiling the binary manually.

# Run directly via npx
npx @ply2splat/native --input input.ply --output output.splat

Python

import ply2splat

# Convert a PLY file to SPLAT format
count = ply2splat.convert("input.ply", "output.splat")
print(f"Converted {count} splats")

# Convert without sorting (faster, but may affect rendering quality)
count = ply2splat.convert("input.ply", "output.splat", sort=False)

# Load PLY file and access individual splats
data = ply2splat.load_ply_file("input.ply")
print(f"Loaded {len(data)} splats")

for splat in data:
    print(f"Position: {splat.position}")
    print(f"Scale: {splat.scale}")
    print(f"Color (RGBA): {splat.color}")
    print(f"Rotation: {splat.rotation}")

# Access splats by index
first_splat = data[0]

# Load existing SPLAT file
data = ply2splat.load_splat_file("output.splat")
print(f"Loaded {len(data)} splats from SPLAT file")

# Get raw bytes for custom processing
raw_bytes = data.to_bytes()

# Load and convert to bytes (for in-memory processing)
data, count = ply2splat.load_and_convert("input.ply")
print(f"Loaded {count} splats, {len(data)} bytes")

JavaScript/TypeScript (Node.js)

import { convert, getSplatCount } from "@ply2splat/native";
import { readFileSync } from "fs";

// Read PLY file into a buffer
const plyBuffer = readFileSync("input.ply");

// Convert to SPLAT format
// Returns { data: Buffer, count: number }
const result = convert(plyBuffer);

console.log(`Converted ${result.count} splats`);
console.log(`Output size: ${result.data.length} bytes`);

// Optionally disable sorting
// const result = convert(plyBuffer, false);

Development

Requirements

• Rust (latest stable)
• Node.js & pnpm (for JS bindings)
• Python & uv (for Python bindings)

Running Tests

# Test the entire workspace
cargo test --workspace

Fuzzing

The crate includes fuzzing targets to ensure stability against malformed inputs.

# Install cargo-fuzz
cargo install cargo-fuzz

# Run fuzzing target
cargo fuzz run fuzz_conversion

Development Environment

This project supports both Nix and Devcontainers for a reproducible development environment.

• Nix: nix develop will enter a shell with Rust and dependencies configured.
• Devcontainer: Open the folder in VS Code and accept the prompt to reopen in container.

License

MIT