openusd

openusd is a Rust implementation of Pixar's Universal Scene Description (USD) format with no C++ dependencies.

Documentation

The following list of docs was used during crate development:

• User documentation
• Book of USD
• API Documentation
• USD Cookbook

For a detailed comparison with the C++ reference implementation and current progress, see the Roadmap.

Features

• Reads all major USD formats: .usda (text), .usdc (binary), and .usdz (archive).
• Composed Stage with full LIVERPS strength ordering (sublayers, inherits, variants, references, payloads, specializes).
• Recursive layer collection with cycle detection, format auto-detection, and expression evaluation.
• List-edit composition (prepend, append, add, delete, explicit) across layers.
• Generic typed field access via Stage::field<T> with TryFrom<Value> conversion.
• Variable expression evaluator for USD's expression syntax.
• Asset resolution with pluggable Resolver trait, filesystem DefaultResolver, and search paths.

If you encounter a file that can't be read, please open an issue and attach the USD file for investigation.

Example

use openusd::{ar, sdf::FieldKey, Stage};

// Open a stage with default settings (DefaultResolver, strict errors).
let stage = Stage::open("scene.usda")?;

// Or configure via the builder:
let stage = Stage::builder()
    // Use a custom asset resolver (default: DefaultResolver).
    .resolver(ar::DefaultResolver::new())
    // Handle composition errors instead of failing (default: hard error).
    .on_error(|err| {
        eprintln!("warning: {err}");
        Ok(()) // skip missing dependency and continue
    })
    .open("scene.usda")?;

// Traverse all prims in the composed scene graph.
stage.traverse(|path| {
    println!("{path}");
})?;

// Read a typed field value (generic over TryFrom<Value>).
let active: Option<bool> = stage.field("/World/Cube", FieldKey::Active)?;

// Access children composed across layers, references, and payloads.
let children = stage.prim_children("/World/Cube")?;
let properties = stage.prim_properties("/World/Cube")?;

Getting started

To begin, simply clone the repository including its submodules. Make sure you have Rust installed on your system, rustup will do the rest.

# Clone the project
git clone --recurse-submodules https://github.com/mxpv/openusd.git
cd openusd

# Use cargo to build, test, lint, etc.
cargo build
cargo clippy

# Run examples
cargo run --example dump_usdc -- ~/caldera/layers/cameras.usd

Minimum supported Rust version (MSRV)

The project typically targets the latest stable Rust version. Please refer to rust-toolchain.toml for exact version currently used by our CIs.

Note

This crate is under active development. No API stability is guaranteed until version 1.0.