Universal Scene Description (OpenUSD) is a high-performance, extensible software platform for collaboratively creating, editing, and simulating complex 3D scenes. OpenUSD is more than a file format and scene representation—it's an extensible framework of libraries, tools, and plugins. This includes the Hydra rendering framework, an open source OpenUSD framework that decouples scene descriptions from renderers, and the Storm renderer, a rasterizer aimed at performance and scalability.

Originally, the Storm renderer only supported OpenGL®. To expand support to the latest generation of APIs, the Hydra Graphics Interface (Hgi) was introduced, providing an abstraction layer for low-level graphics APIs. A few years ago, the HgiMetal backend was added to support Apple's Metal API, enhancing the renderer's capabilities on macOS and iOS. Today, we are excited to announce experimental support for the Khronos® Vulkan® API through the HgiVulkan backend, available in OpenUSD 24.08. This allows developers to start leveraging Vulkan in Storm or other Hgi-based renderers, although there are some known limitations and performance issues that are being addressed.

This work has been a collaborative effort between Alliance for OpenUSD (AOUSD) members Pixar, Autodesk, and Adobe, aiming to bring HgiVulkan to feature parity with the existing OpenGL and Metal backends within USD/Hydra. Our goal includes achieving improved performance over the OpenGL backend on Linux and Windows, making Vulkan a more compelling option for developers on these platforms. We are also expanding unit testing support on Linux, with plans to extend this to Windows and Mac in the near future. Currently, the majority of existing imaging unit tests in OpenUSD pass when run with the HgiVulkan backend on Linux, and we have added several HgiVulkan-specific unit tests for this platform.

In addition to Linux and Windows, Vulkan support extends to Android mobile devices, broadening the USD/Hydra platform's reach and enabling developers to create high-performance 3D applications for a wider range of devices.

All of OpenUSD, Hydra, and Storm are open source. For more information, visit the OpenUSD GitHub repository. For a deeper dive into this project, see the “Adding Vulkan to Pixar’s Hydra Storm Renderer” presentation at the “Vulkan, Forging Ahead” BOF session at SIGGRAPH 2024 on July 31, 2024. Learn more on the SIGGRAPH program website.