Three independently-built but co-developed Python projects in one repository. The merge from the standalone ovui and USD Viewer (ovgear) repos preserves the full history of both.

.
├── ovui/                  ← UI framework: omni.ui + omni.ui_scene + native libs
├── ovwidgets/             ← Application widgets layer (stage / layers / property /
│                            content / viewport / app) with per-component dists
└── ovui-data-adapters/    ← Adapter contracts (common) + OpenUSD adapters (openusd)

Each top-level directory is a self-contained project root. They are co-located so a single PR can change framework code, widget code, and adapter code in lock-step, but they install and ship as independent distributions:

• ovui/setup.py builds the native UI framework (cmake + ninja
  • setuptools) and ships as the ovui wheel.
• ovwidgets/dist/{all,app,common,content,layers,property,stage,viewport}/pyproject.toml ship as ovwidgets-<sub> distributions; per-component install uses where = ["../.."].
• ovui-data-adapters/dist/{common,openusd}/pyproject.toml ship as ovui-data-adapters-{common,openusd}; same where = ["../.."] pattern, source under the unified ovui-data-adapters/ovui_data_adapters/ import-package root.

• ovui/README.md — UI framework
• ovwidgets/README.md — application widgets
• ovui-data-adapters/README.md — adapter contracts and OpenUSD adapters

For a fresh dev venv:

python3.12 -m venv ovwidgets/_venv312
ovwidgets/_venv312/bin/pip install -U pip setuptools wheel build pytest pytest-asyncio ruff mypy
ovwidgets/_venv312/bin/pip install -e ovui/
ovwidgets/_venv312/bin/pip install -e /path/to/ovrtx/python      # external dep
ovwidgets/_venv312/bin/pip install -e ovui-data-adapters/dist/common
ovwidgets/_venv312/bin/pip install -e ovui-data-adapters/dist/openusd
# then install ovwidgets/dist/<sub>/ packages in dependency order.

Windows source installs need the Windows prerequisites in ovui/README.md before pip install -e ovui/. Install the CUDA Toolkit before building if you need the CUDA-Vulkan byte-image path used by ovui/examples/byte_image_gpu_demo.py, then verify with:

python -c "import omni.ui as ui; print(ui.has_gpu_byte_image())"

The active automation lives under .github/workflows/:

• build-wheel.yml builds ovui wheels for Linux x64, Linux ARM64, and Windows x64, then smoke-imports the installed wheel.
• headless-lavapipe.yml and headless-egl.yml build and run the headless CTest lanes.
• test-b1-vulkan.yml, test-b2-vulkan-asan.yml, and test-b3-egl.yml run the Vulkan pytest, native ASan, and EGL pytest lanes.
• generate-goldens.yml regenerates golden images on demand.

The repository was merged from two sources:

• ovui — relocated under ovui/.
• USD Viewer (ovgear) — split into ovwidgets/ (the import package + its dist packages) and ovui-data-adapters/ (the unified adapter package).

Merge history is preserved in git; the runtime and packaging docs above are the current source of truth.