Autodesk is extending the Hydra framework inside OpenUSD to add new capabilities. Hydra (prefix "Hd") is the OpenUSD framework that "enables the communication between multiple scene graphs and multiple renderers." This presentation from SIGGRAPH 2019 explains more about Hydra.
This repository has links to the proposals, branches, and pull requests for Autodesk's Hydra contributions. As these are contributions to OpenUSD, the code is intended for the OpenUSD repository and is not stored here. While work is in progress, the code for these and other OpenUSD contributions from Autodesk can be found in the Autodesk fork of OpenUSD.
Also listed below are other Autodesk projects related to Hydra, but that are separate from OpenUSD itself.
All work is shared under the same license as OpenUSD. For more information, you can contact us at [email protected].
📣 New in August 2025: Hydra Viewport Toolbox
Proposal (plus latest proposed update)
Branch 1 / Branch 2 and Pull Request 1 / Pull Request 2
Proposal (plus latest proposed update)
Branch and Pull Request
- Generate optimal MaterialX shaders via lobe pruning (pull request).
- Persistent run-time-populated MaterialX code generation cache (pull request).
- Parallel MaterialX code generation (pull request).
Proposal (PR) and Branch and Pull Request
A set of components and tools to use the Arnold renderer with OpenUSD, including a Hydra render delegate.
A real-time GPU path-tracing renderer with a Hydra render delegate, intended for viewport display.
A Maya plug-in that replaces the main Maya viewport with a Hydra viewer.
A collection of utilities to support graphics viewports using OpenUSD Hydra.
Autodesk actively contributes to both MaterialX and OpenPBR. The Autodesk fork of MaterialX has the latest contributions to that project.