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.

Schema

Geometry is defined with the USDGeom schema.

Requirements & Recommendations

Tags	Summary	Compatibility	Validator
🔑	Assets must contain at least one Imageable Geometry	core-usd
🔑	Geometry shall be defined as such that the asset is correctly positioned and oriented at the origin (0,0,0).	core-usd
🔑	All geometry shall be represented as non-subdivided mesh primitives using the UsdGeomMesh schema.	core-usd
✅	Mesh geometry must be manifold	core-usd	latest+
✅	Mesh topology must be valid	core-usd	latest+
✅	Transparent physical bodies should be watertight to allow for simulation of light transmission and refraction.	core-usd
✅	Meshes should be positioned with xform ops rather than by “baking” transformations into point positions.	core-usd
✅	Repeated occurrences of identically shaped objects should have identical mesh connectivity	core-usd	Manual
✅	The pivot point of an asset should be positioned logically: at the center of the object’s base for ground plane objects, and at the center of rotation for objects that rotate around specific points.	core-usd
✅	All non-subdivided meshes must have normals.	core-usd	latest+
✅	Mesh normals values must be valid to produce correct shading.	core-usd
✅	The winding order of faces in a mesh must correctly represent the orientation (front/back) of the face.	core-usd
⛔	World space bounds must not exceed RTX limit.	rtx
🚀	Boundable geometry primitives must have valid extent values.	open-usd
🚀	Only include geometry that contributes to visualization or simulation	open-usd
🚀	Use efficient mesh boundaries for performance	rtx
🚀	Meshes should maintain appropriate scale and boundary volumes	rtx
🚀	Meshes should not overlap unnecessarily	core-usd
🚀	Meshes should not share the exact same space	core-usd
🚀	Use indexed primvars when values are repeated	core-usd	latest+
🚀	Use subdivision only when needed for smooth surfaces or displacement	core-usd	latest+
🚀	Only include primvars that are actively used	core-usd	latest+
🚀	Combine small meshes into larger ones where appropriate	core-usd
🚀	Use appropriate tessellation density for geometry	core-usd
🚀	Use time samples only when attribute values change	core-usd
🚀	Each vertex position should be unique	core-usd	latest+
🚀	Avoid tessellating primitive shapes	core-usd
🚀	Mesh topology should be without unused vertices, edges, or faces.	core-usd	latest+
🚀	Faces should have non-zero area.Faces where all vertices are co-linear or coincident waste memory and can cause rendering artifacts.	core-usd	latest+
🚀	The values of points must not exceed the limit at which a given precision can be represented using 32-bit floats.	core-usd
🚀	Meshes must be triangulated for optimal rendering performance and compatibility when considering automatic collider creation (convex-hull, convex-decomposition, etc…). Triangulating mesh will provide predictable results versus n-gons.	core-usd