Requirements#

Summary#

An Asset needs to include at least one USDGeom primitive with a computed purpose of “render” or “default”.
The USDGeom prim must have a valid topology.
The USDGeom primitive should not create performance issues for raytraced rendering and simulation.

Geometry is defined with the USDGeom schema.

Tags	Summary	Compatibility	Validator
🔑	All prims in the hierarchy must be direct or indirect descendents of a single root root prim, preventing scattered or disconnected Xform hierarchies.	other
🔑	Every UsdGeomGprim must have a parent Xform with specific transform operations and hierarchy constraints.	other
🔑	The root prim of a hierarchy must be transformable, meaning its’ prim type must inherit from UsdGeomXformable and be capable of receiving transform operations.	other
🔑	Stage must specify a default prim to define the root entry point.	other
🔑	All prims representing distinct objects or groups that require placement, posing or animation shall inherit from UsdGeomXformable.	other
❓	This is a placeholder requirement to maintain sequential numbering in the hierarchy requirements.	other
❓	Geometry should be grouped under parent Xforms in a way that is logical for the object’s structure and intended use in layouts or simulations.	other
🔑	Assets must not contain undefined prims (overs)	other	latest+
✅	Transformations (translate, rotate, scale, pivot) on prims that are intended to be translated, rotated or scaled by users (e.g. the root prim of an asset) should conform to the UsdGeomXformCommonAPI.	core-usd
✅	For assets (e.g., a robot with multiple articulated joints), the hierarchy should reflect the kinematic chain, with appropriate Xforms for each transformable link.	open-usd