Add initial documentation for experimental OpenUSD support in MuJoCo.

PiperOrigin-RevId: 789365870 Change-Id: I19cce03ec2ffc28cdf4252bfd02c8b5163bb5ba2
2025-07-31 09:29:38 -07:00
parent 32c7d3f085
commit 700da7c5bd
7 changed files with 349 additions and 0 deletions
@@ -0,0 +1,63 @@
+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.