Getting Started

Getting Started — OpenUSD Exchange SDK

When to apply

Apply the first time a task asks to install OpenUSD Exchange, set up a new project, run a script that imports usdex.core / usdex.rtx / usdex.test, or stand up a native (C++) build that links usdex_core / usdex_rtx. Stop applying once the project layout, virtual environment, and smoke test pass.

Hard rules — read first

Two recurring failures must be prevented before any other work happens.

1. Never build the usd-exchange repository yourself to use it. The SDK ships as Python wheels on PyPI and PyPI NVIDIA, and as precompiled C++ binaries via the install_usdex script. Building from source is only for contributors changing the SDK itself. If a task says "use the OpenUSD Exchange SDK", install the wheel (Python) or run install_usdex (C++).
2. Never place your new project inside the usd-exchange repository directory. Create the project in its own directory, with its own virtual environment. The usd-exchange clone (if any) is a read-only reference; the user's converter / pipeline / sample lives elsewhere and pulls in the SDK as a dependency. Do not cd into the usd-exchange checkout to create files for the user's project.

Choose the install path

Pick the wheel unless the user explicitly needs C++, a non-default OpenUSD version, or a non-default Python version. The wheel locks the OpenUSD version per release; only install_usdex exposes --usd-version, --usd-flavor, --python-version, --install-rtx, --install-test, --install-extra-plugins.

Project layout

Create a fresh directory anywhere outside the usd-exchange clone. Recommended layout for a Python project:

• .venv/ — virtual environment.
• src/ — converter / pipeline source.
• tests/ — unittest suite using usdex.test (optional).
• output/ — generated USD assets and textures.
• pyproject.toml or requirements.txt — dependencies.

For a native C++ project, follow the layout in docs/native-application.md: a project root with the SDK installed under usdex/ (alongside target-deps/usd, target-deps/python, and <platform>/<config>/lib).

Python install (wheel)

Linux (bash):

• python -m venv .venv
• source .venv/bin/activate
• pip install "usd-exchange[test]" — drop [test] if you do not need usdex.test / Asset Validator

Windows (PowerShell):

• python -m venv .venv
• .venv\Scripts\Activate.ps1
• pip install "usd-exchange[test]"

Verify: python -c "import usdex.core; print(usdex.core.version())" should print a version string.

Native (C++) install via install_usdex

Run from a clone of either usd-exchange or the Exchange Samples. When run from the Samples repo, run ./repo.sh build --fetch-only (or .\repo.bat build --fetch-only) first.

• Release: ./repo.sh install_usdex --config release --install-python-libs
• Debug: ./repo.sh install_usdex --config debug --install-python-libs
• Pin OpenUSD: add --usd-version 25.05 (and --python-version 3.11 if needed)
• RTX MDL helpers (usdex_rtx): add --install-rtx
• Test helpers + Asset Validator: add --install-test
• Monolithic / no-Python OpenUSD: --usd-flavor usd-minimal --python-version 0

The output goes to _install/. Deep-copy it (preserving symlinks/junctions) into the project's usdex/ folder:

• Linux: cp -Lr _install $project_root/usdex
• Windows: robocopy /s _install $project_root\usdex > NUL

Do not copy without preserving links — target-deps/ contains soft links on Linux and junctions on Windows.

For include paths, libraries, preprocessor defines, and runtime path setup, follow docs/native-application.md (Makefile and Visual Studio settings included). The Makefile and repo.toml snippets there are the canonical reference; do not invent build flags.

Smoke test

Run from inside the project directory with the venv active before writing converter code. Exercises stage creation, naming, transforms, save, and the diagnostic delegate — failures here mean the install is wrong. Names go through getValidPrimName / NameCache rather than literal name= arguments, matching the authoring rules.

import usdex.core
from pxr import Gf, UsdGeom

AUTHORING_METADATA = "my-converter smoke test, version 0.1"
asset_name, probe_name = "World", "Probe"

usdex.core.activateDiagnosticsDelegate()
cache = usdex.core.NameCache()
stage = usdex.core.createStage("smoke.usda", usdex.core.getValidPrimName(asset_name),
    UsdGeom.GetFallbackUpAxis(), UsdGeom.LinearUnits.centimeters, AUTHORING_METADATA)
assert stage
root = usdex.core.defineXform(stage.GetDefaultPrim()).GetPrim()
usdex.core.defineXform(root, cache.getPrimName(root, probe_name),
    Gf.Transform(Gf.Matrix4d().SetTranslate(Gf.Vec3d(0, 100, 0))))
usdex.core.saveStage(stage, AUTHORING_METADATA)
print(f"OK: usdex {usdex.core.version()}")

If this runs and writes smoke.usda, the install is healthy. If usdex.core fails to import, you are running the wrong interpreter — re-activate the venv.

Next

After the smoke test passes, move to the usd-authoring skill for authoring rules and the topical reference index. The samples repo (usd-exchange-samples) is the canonical end-to-end reference; clone it for working examples and run them via ./run.sh <sample> (C++) or python source/python/<sample>.py.

Source: NVIDIA-Omniverse/usd-exchange — distributed by TomeVault.