Pixar Universal Scene Description (USD)

What Is Universal Scene Description?


Universal Scene Description (USD) is an easily extensible, open-source 3D scene description and file format developed by Pixar for content creation and interchange among different tools. As a result of its power and versatility, it’s being widely adopted, not only in the visual effects community, but also in architecture, design, robotics, manufacturing, and other disciplines.



Pixar Universal Scene Description (USD)



USD at NVIDIA


USD is the foundation for NVIDIA Omniverse™, a live collaborative platform that connects a wide variety of content creation tools to each other and to our real-time NVIDIA RTX™ ray tracer. Learn more about NVIDIA Omniverse and sign up for updates here.

NVIDIA has expanded upon USD by developing new tools, integrating technologies and providing samples and tutorials.


Showcase piece created by NVIDIA to illustrate the power of RTX on the Omniverse Platform. Marbles was created by a distributed team of artists and engineers in Omniverse, assembling VFX+ quality USD assets into a fully physically simulated game level. Marbles runs on a single Quadro RTX 8000 simulating complex physics in a real-time ray traced world.

Learn more about USD's history and how we use it ourselves at NVIDIA: To 3D and Beyond: Pixar’s USD Coming to an Industry Near You


USD Pre-built Libraries and Tools


Tutorials


  • 00:00 - Platform Overview
  • 01:25 - Technology Stack
  • 03:17 - Video Tutorials
  • 03:38 - Kit Extension System
  • 05:16 - Extension Manager
  • 05:30 - Simplest Extension
  • 05:50 - Extension Dependencies
  • 06:31 - Kit Application
  • 06:57 - Python Extension
  • 07:21 - Kit SDK Samples
  • 08:36 - Omni.UI
  • 09:32 - Omni.UI Documentation
  • 10:23 - Omni.UI Dynamic Syntax
  • 11:54 - Omni.UI Graph Framework
  • 12:26 - Model-View-Controller Pattern
  • 13:04 - Full Model API
  • 13:18 - Example Application
  • 14:01 - Important APIs - Treeview Widget
  • 15:24 - Important APIs - The Web in Kit
  • 16:24 - Important APIs - Web Streaming
  • 17:50 - Nucleus-Based Microservices
  • 18:42 - Kit-Based Microservices
  • 19:01 - Omni.kit.controlport
  • 19:36 - Kit Microservices with Rendering
  • 20:00 - Technology Preview - Quick Search
  • 22:02 - Technology Preview - Omni.UI Inspector
  • 24:00 - Omniverse Kit Recap

Now that you have had a good overview of the platform and its components we suggest you take some time to learn about USD which is at the center of Omniverse.

Getting Started with USD for Collaborative 3D Workflows

In this self-paced course, participants will learn how to generate a scene using human-readable Universal Scene Description ASCII (.USDA) files. Upon completion, participants will be able to create their own scenes within the USD framework and will have a strong foundation to use it in applications such as Omniverse, Maya, Unity, and Unreal Engine.

There are two sections to this training:

  • USD Fundamentals: An introduction to the basics of USD, no programming knowledge required.
  • Advanced USD: A demonstration of how to use Python to generate USD files.



Try the course



USD Sample Assets

Marbles USD sample scene


NVIDIA Marbles Sample
USD scene with MDL materials rendered in Omniverse USD scene with MDL materials rendered in Omniverse


NVIDIA USD Attic Sample
Creative Commons License
This work is licensed under a
Creative Commons Attribution 4.0 International License.

Download
USD sample scene


PIXAR Kitchen Set

You will need to review and accept Pixar’s license agreement before downloading the file.


Download from PIXAR
ALab USD sample scene


Animal Logic - USD ALab

The USD ALab data set is the Animal Logic interpretation and implementation of real world production and pipeline concepts. There are two downloads available, including guiding documents and two sets of textures.


Read Me Download from Animal Logic

Material Definition Language (MDL) Schema

USD is agnostic about the way material properties are represented. At NVIDIA, we believe artists should be able to author materials for cinema-quality rendering and have an automated process that produces simpler but still high-quality shaders in real time.


To achieve this, NVIDIA has developed MDL, an open-source, GPU-friendly Material Definition Language with an associated distiller that simplifies shaders for preview and virtual reality (VR) applications. The NVIDIA MDL SDK has been adopted by many application developers, including Adobe®, Allegorithmic, and Epic’s Unreal Studio.

To facilitate its use, we’ve created a specification (MDL Schema) for referencing MDL in USD and have developed Omniverse plug-ins to facilitate MDL-based workflows. MDL enjoys wide and increasing adoption in the design, visual effects, and gaming industries, among others.

MDL material examples

USD Physics


Additional Resources

USD and Hydra Resources


 

Pixar's USD Documentation

 

Glossary of USD Terminology

 

[Siggraph 2019] Rob Stauffer’s video introduction to USD

 

[Siggraph 2019] Pixar overview of USD and Hydra

 

[Colin Kennedy] USD-Cookbook

 

[vfxpro99] Help with building USD

 

[vfxpro99] USD Resources

 

[Before & Afters] USD: What it is and why it matters

 

[Before & Afters] How does USD actually get used at a VFX studio?

 

[GTC 2015] Hydra presentation by Jeremy Cowles