Pixar's Universal Scene Description (USD) Core Python Library

Warnings

• breaking Python 3.8 support is deprecated as of a recent OpenUSD release (noted in CHANGELOG) and will be removed in the subsequent release. Users on Python 3.8 should plan to upgrade.
  Fix: Upgrade your Python environment to 3.9 or higher (up to <3.14 as per PyPI).
• gotcha The `usd-core` PyPI package provides only the core USD libraries for authoring, composing, and reading. It *does not* include optional plugins, imaging features, or tools like `usdview` (Pixar's scene inspector). For a full USD experience, including `usdview` and other utilities, you generally need to download pre-built binaries from NVIDIA or build OpenUSD from source.
  Fix: If `usdview` or full imaging capabilities are needed, refer to NVIDIA's OpenUSD developer resources for pre-built binaries or the OpenUSD GitHub repository for build instructions.
• deprecated The older `displayName`, `displayGroup`, and `hidden` metadata APIs within `UsdUI` were deprecated in v25.11 in favor of a new, dictionary-valued `uiHints` metadata field.
  Fix: Migrate UI metadata to use the `uiHints` dictionary for prims and properties, which supports features like `shownIf` and `valueLabels`.
• breaking Beginning with the 26.03 release, the `usd-core` PyPI package utilizes the C++11 ABI. Furthermore, clients building C++ code against OpenUSD with Visual Studio must enable the `/permissive-` (strict standards conformance) flag.
  Fix: Ensure your C++ toolchain and project settings are updated to be compatible with C++11 ABI and, for Visual Studio, enable the `/permissive-` flag.
• deprecated Support for negative layer offset scale has been removed, and the `PCP_ALLOW_NEGATIVE_LAYER_OFFSET_SCALE` environment variable has been removed. Additionally, the `SDF_FILE_FORMAT_LEGACY_IMPORT` environment variable is now set to 'warn' by default, indicating that legacy `.sdf` file format header support will be removed in a future release.
  Fix: Avoid using negative layer offset scales. For `.sdf` files, ensure they are in a modern format to prevent future compatibility issues.
• gotcha Users on Windows running Python 3.8+ within `conda` environments may encounter DLL loading failures (e.g., `DLL load failed while importing _tf`). This was addressed in USD 22.03.
  Fix: Ensure you are using a recent `usd-core` version (22.03 or newer). As a workaround for older versions or persistent issues, setting the environment variable `CONDA_DLL_SEARCH_MODIFICATION_ENABLE=1` might resolve the problem.

Install

• pip install usd-core Install core USD Python library
• pip install usd-core types-usd Install with auto-complete types (optional)

Imports

• Usd, UsdGeom, Sdf, Gf

  from pxr import Usd, UsdGeom, Sdf, Gf

  USD Python modules are nested under the 'pxr' namespace.

Quickstart

This quickstart demonstrates how to create a simple USD stage, define a transform (Xform) and a sphere (UsdGeom.Sphere) prim, set an attribute, and save the stage to a .usda file. All core USD Python modules are accessed via the `pxr` namespace.

from pxr import Usd, UsdGeom
import os

# Create a new USD stage in memory or on disk
output_filename = os.environ.get('USD_OUTPUT_FILE', 'HelloWorld.usda')
stage = Usd.Stage.CreateNew(output_filename)

# Define a root transform prim at the path /hello
xformPrim = UsdGeom.Xform.Define(stage, '/hello')

# Define a sphere prim nested under the transform at /hello/world
spherePrim = UsdGeom.Sphere.Define(stage, '/hello/world')

# Set a radius for the sphere
spherePrim.GetRadiusAttr().Set(2.0)

# Save the stage to a file
stage.GetRootLayer().Save()

print(f"Created {output_filename} with a sphere at /hello/world")