Universal Scene Description for .NET

Pixar's OpenUSD - Universal Scene Description - packaged as a single, drop-in NuGet for .NET 10. Bundles the managed bindings, the native USD runtime, and the Pixar plugin tree under the standard runtimes/<rid>/native/ NuGet convention, so the .NET SDK automatically deploys everything into your output folder. No build steps, no environment variables, no plugin registration code.

USD is a high-performance extensible software platform for collaboratively constructing animated 3D scenes, designed to meet the needs of large-scale film and visual effects production.

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Install

dotnet add package UniversalSceneDescription

Quick start

using UniversalSceneDescription;
using pxr;

// Configures the native loader and registers the bundled Pixar plugin tree.
// Idempotent and thread-safe - call once at startup.
UsdRuntime.Initialize();

using var stage = UsdStage.CreateNew("hello.usda");
UsdGeomXform.Define(stage, new SdfPath("/Hello"));
UsdGeomSphere.Define(stage, new SdfPath("/Hello/World"));
stage.Save();

That's it. The UsdRuntime.Initialize() call points USD at the usd/ plugin folder that the .NET SDK dropped next to your executable, and makes sure the OS loader can resolve the native DLLs.

What's in the box

Component	Source	Where it lands
Managed USD.NET.dll (pxr.* SWIG bindings)	Unity com.unity.usd.core	lib/net10.0/
Native USD runtime (usd_*, UsdCs, tbb, Imath, Alembic, per platform extension)	Pixar OpenUSD (Unity com.unity.usd.core distribution)	runtimes/<rid>/native/
Pixar plugin tree (plugInfo.json + generated schemas for usdGeom, usdShade, usdSkel, usdLux, usdPhysics, usdRender, …)	Pixar OpenUSD	runtimes/<rid>/native/usd/
UniversalSceneDescription.UsdRuntime helper	this package	UniversalSceneDescription namespace

The .NET SDK auto-deploys everything under runtimes/<rid>/native/ to your build output (preserving the usd/ subdirectory layout) - dotnet run, dotnet test, and dotnet publish all just work.

Configuration

Override the plugin location at runtime:

UsdRuntime.Initialize(
    pluginPath: "/custom/path/to/usd",
    nativeLibraryDirectory: "/custom/path/to/native");

To suppress the bundled native runtime entirely (rare - only useful if you ship your own USD build):

<PackageReference Include="UniversalSceneDescription" Version="7.1.0">
  <ExcludeAssets>runtime</ExcludeAssets>
</PackageReference>

Opt out of the automatic plugin-tree staging (rare - only needed if you want to stage the usd/ plugin folder somewhere other than next to the executable, or you ship your own USD build):

<PropertyGroup>
  <DisableUsdPluginStaging>true</DisableUsdPluginStaging>
</PropertyGroup>

Platform support

Runtime identifier	Status	Native asset folder
win-x64	✅ Shipping	runtimes/win-x64/native/
linux-x64	✅ Shipping	runtimes/linux-x64/native/
osx-x64	✅ Shipping	runtimes/osx-x64/native/
osx-arm64	✅ Shipping	runtimes/osx-arm64/native/

The csproj globs runtimes/**/*, so refreshing any per-RID folder with a newer platform USD build is enough to ship updated native support - no csproj edit needed. Each per-RID folder includes runtime notes and currently ships binaries from Unity's com.unity.usd.core plugin distribution.

UsdRuntime itself is fully cross-platform: on Linux it prepends the native directory to LD_LIBRARY_PATH, on macOS to DYLD_LIBRARY_PATH and DYLD_FALLBACK_LIBRARY_PATH, on Windows to PATH. PXR_PLUGINPATH_NAME is set on every platform so libplug discovers the bundled plugin tree.

Learn USD

• Introduction to USD
• Tutorials
• FAQ
• Toolset
• NVIDIA USD resources & samples
• Pixar demo assets

Credits

• Pixar Animation Studios - authors of OpenUSD.
• Unity Technologies - the managed C# bindings vendored here are extracted from the com.unity.usd.core package.
• 3DEngine - packaging and .NET 10 helper API.

License

MPL-2.0 - see file for details. OpenUSD itself is licensed under the Modified Apache 2.0 License.

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Issues, PRs and contributions welcome at github.com/EggyStudio/UniversalSceneDescription.