vocabulary: "1.0.0"

info:
  provider: Alliance for OpenUSD
  description: >-
    Vocabulary covering the OpenUSD specification and API including core
    concepts, schema domains, file formats, composition arcs, and the
    developer tooling ecosystem for Universal Scene Description.
  created: "2026-04-19"
  modified: "2026-04-19"

operational:
  apis:
    - name: OpenUSD C++ API
      namespace: openusd-cpp
      version: "25.02"
      baseUrl: https://openusd.org/release/api/index.html
      status: active
    - name: OpenUSD Python Bindings
      namespace: openusd-python
      version: "25.02"
      baseUrl: https://pypi.org/project/usd-core/
      status: active

  resources:
    - name: layers
      description: USD layers — files or in-memory containers for scene description data.
      apis: [openusd-cpp, openusd-python]
      actions: [create, open, save, flatten, sublayer]
    - name: prims
      description: USD prims — named nodes in the scene hierarchy.
      apis: [openusd-cpp, openusd-python]
      actions: [create, get, define, override, delete, traverse]
    - name: attributes
      description: Typed, time-sampled data values on prims.
      apis: [openusd-cpp, openusd-python]
      actions: [create, get, set, clear, block]
    - name: relationships
      description: Targetted connections between prims.
      apis: [openusd-cpp, openusd-python]
      actions: [create, get, set, clear]
    - name: stages
      description: In-memory composed scene graphs assembled from layer stacks.
      apis: [openusd-cpp, openusd-python]
      actions: [create, open, export, flatten]
    - name: variants
      description: Named alternatives for prim content allowing switchable configurations.
      apis: [openusd-cpp, openusd-python]
      actions: [create, select, clear]

  actions:
    - name: create
      description: Create a new resource (layer, stage, prim, attribute).
      pattern: write
    - name: get
      description: Retrieve a resource by path or identifier.
      pattern: read
    - name: set
      description: Set the value of an attribute or relationship.
      pattern: write
    - name: define
      description: Define a prim with a typed schema (def specifier).
      pattern: write
    - name: override
      description: Create an over prim spec for non-destructive overrides.
      pattern: write
    - name: traverse
      description: Walk the prim hierarchy of a stage or layer.
      pattern: read
    - name: flatten
      description: Flatten composed layers into a single layer.
      pattern: write
    - name: open
      description: Open an existing layer or stage from a file path.
      pattern: read
    - name: save
      description: Save a layer to disk.
      pattern: write
    - name: export
      description: Export a stage or layer to a file.
      pattern: write

  schemas:
    core:
      - name: USDLayer
        description: A USD layer containing prim specs, property specs, and metadata.
        key_properties: [identifier, fileFormat, defaultPrim, startTimeCode, endTimeCode, framesPerSecond, upAxis]
      - name: USDPrim
        description: A named node in the USD scene hierarchy with optional type schema.
        key_properties: [path, name, typeName, specifier, active, kind, purpose]
    geometry:
      - name: UsdGeomMesh
        description: A polygonal mesh geometry prim with points, face vertex counts, and indices.
      - name: UsdGeomXform
        description: A transform container prim with local-to-parent transformation stack.
      - name: UsdGeomCamera
        description: A camera prim with projection, aperture, and clipping parameters.
    shading:
      - name: UsdShadeShader
        description: A shader node in a material network with typed inputs and outputs.
      - name: UsdShadeMaterial
        description: A material prim binding shading networks for surface, displacement, and volume.

  enums:
    specifier:
      - def
      - over
      - class
    file_format:
      - usda
      - usdb
      - usd
      - usdz
    up_axis:
      - Y
      - Z
    kind:
      - ""
      - model
      - group
      - assembly
      - component
      - subcomponent
    purpose:
      - default
      - render
      - proxy
      - guide
    prim_type:
      - Xform
      - Mesh
      - Sphere
      - Cube
      - Cone
      - Capsule
      - Cylinder
      - Camera
      - SkelRoot
      - Skeleton
      - SkelAnimation
      - Material
      - Shader
      - NodeGraph
      - DistantLight
      - SphereLight
      - RectLight
      - DomeLight