OpenUSD

.. toctree:: :hidden:

building
mjcPhysics
mjcf_file_format_plugin
importing
exporting

.. WARNING:: OpenUSD support is currently experimental and subject to frequent change.

Introduction

This chapter describes MuJoCo's support for OpenUSD <https://openusd.org/release/intro.html>__. USD (Universal Scene Description) is an open-source framework developed by Pixar for describing 3D scenes. MuJoCo's integration allows users to leverage USD's rich ecosystem and tooling.

What is OpenUSD?

USD is a high-performance, extensible system for describing, composing, simulating, and collaborating on 3D data. Originally developed by Pixar Animation Studios, USD is now used across various industries, including visual effects, animation, gaming, and robotics, to streamline complex 3D workflows. It provides a common language for different software applications to exchange 3D scene information.

Why do we care about OpenUSD?

Integrating USD with MuJoCo offers several advantages:

Interoperability: USD is supported by a wide range of 3D content creation tools (e.g., Houdini, Maya, Blender). This allows MuJoCo users to easily import scenes and assets created in these tools.
Rich Scene Description: USD provides a powerful and flexible way to represent complex scenes, including geometry, materials, lighting, and hierarchies.
Collaboration: USD's layering and composition features enable powerful and efficient non-destructive authoring pipelines.

USD support overview

Import: You can load USD assets (specifically .usd, .usda, .usdc, .usdz files) into MuJoCo via MJCF or dragging and dropping into :ref:simulate.cc <saSimulate>.
Schemas: MuJoCo primarily uses the standard UsdPhysics <https://openusd.org/dev/api/usd_physics_page_front.html>__ schemas for representing physics properties.
Extensions: Custom :doc:mjcPhysics schemas are provided to cover MuJoCo-specific features not available in UsdPhysics.
MJCF File Format Plugin: A :doc:mjcf_file_format_plugin allows treating MJCF files as USD layers in any native USD application.
Export: MuJoCo scenes can be exported to USD.

Where do I learn more about USD?

Remedy's Book of USD <https://remedy-entertainment.github.io/USDBook>__: Friendly introduction to USD.
Official OpenUSD Documentation <https://openusd.org/release/intro.html>__: Official documentation for API and implementation details.
Pixar's USD Introduction <https://graphics.pixar.com/usd/release/index.html>__: Simple example usage of USD.
NVIDIA's USD Resources <https://developer.nvidia.com/usd>__: Set of USD resources primarily concerned with asset structure.