Requirements Index

Core

Atomic Asset

Tags	Summary	Compatibility	Validator
🔑	Asset references should use anchored paths	core usd	latest+
🔑	Asset must use only supported file types	openusd	latest+
⛔	Texture UDIMs are not supported in USDZ files in NVIDIA Omniverse	kit	latest+

Units

Tags	Summary	Compatibility	Validator
🔑	Stage must specify upAxis to define the orientation of the stage	core usd	latest+
🔑	Stage must specify metersPerUnit to define the linear unit scale	core usd	latest+
🔑	Stage must specify upAxis = “Z” to define the orientation of the stage	core usd
🔑	Stage must specify metersPerUnit = 1.0 to define the linear unit scale	core usd	latest+
✅	Stage must specify kilogramsPerUnit to define the mass unit scale, if physics objects are present in the stage.	core usd
✅	Must apply corrective transforms for different units	core usd
✅	Stage must specify timeCodesPerSecond, if timesamples are present in the stage.	core usd

Visualization

Geometry

Tags	Summary	Compatibility	Validator
🔑	Assets must contain at least one Imageable Geometry	core usd
🔑	Asset transforms shall be defined such that the asset is correctly positioned and oriented at the origin (0,0,0).	core usd
🔑	Transforms and pivots should be positioned at intuitive points on the asset to ensure expected behavior during placement and rotation.	core usd	Manual
🔑	All geometry shall be represented as mesh primitives using the UsdGeomMesh schema.	core usd
✅	Mesh geometry must be manifold	core usd	latest+
✅	Mesh topology must be valid	core usd	latest+
✅	Meshes should be positioned using transformations, not by embedding positions into point positions.	core usd
✅	Repeated occurrences of identically shaped objects should have identical mesh connectivity	core usd	Manual
✅	Normals should be authored to accurately represent the intended surface appearance.	core usd	Manual
⛔	UsdGeomMesh (that is not utilizing subdivision) needs to have normal attributes.	rtx
⛔	World space bounds must not exceed RTX limit.	rtx	latest+
🚀	Boundable geometry primitives should have valid extent values.	openusd	latest+
🚀	Only include geometry that contributes to visualization or simulation	openusd
🚀	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+
🚀	Do not subdivide meshes with Normals.	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.	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	latest+
🚀	Use appropriate vertex count for geometry	core usd
🚀	Meshes should use instancing if they are identical apart from their world space location	core usd
🚀	Use appropriate mesh count for scene	rtx

Materials

Tags	Summary	Compatibility	Validator
✅	Material bindings must use appropriate scope to ensure proper material assignment and inheritance.	open usd	latest+
✅	MDL material source assets must be properly referenced and accessible to ensure material loading and rendering.	open usd	latest+
✅	MDL Shaders must standard OpenUSD shader source attributes to ensure compatibility.	kit 107.0+	latest+
✅	Material attributes must comply with the UsdPreviewSurface specification to ensure consistent rendering and viewer compatibility.	open usd	latest+
🚀	Using fewer materials can result in better performance.	open usd	latest+

Ground Truth

Semantic Labels

Tags	Summary	Compatibility	Validator
🔑	All geometry prims must be semantically labeled.	core usd	latest+
✅	Semantic labels must use the SemanticsLabelsAPI schema	open usd	latest+
✅	If the Wikidata ontology is used, Q-Codes must be valid, properly formatted, and retrievable from wikidata.org.	nvidia omniverse	latest+
⛔	Semantic label attributes must not contain time samples	rtx	latest+

Dense Captions

Tags	Summary	Compatibility	Validator
🔑	The Root Prim must inlcude documentation metadata that describes the 3D Asset.	core usd
💎	Prims representing sub-objects or parts within the asset should be documented with additional dense captions.	core usd

Non-Visual Sensors

Non-Visual Surface Properties

Tags	Summary	Compatibility	Validator
🔑	Materials must specify additional “non-visual” material attributes	rtx	latest+
✅	Materials must specify a base material type	rtx	latest+
✅	Materials must specify surface coating	rtx	latest+
✅	Attributes must be on bound materials	rtx
✅	Properties must be consistent with visual materials	rtx
✅	Properties must not be time-varying	rtx	latest+

Physics

Rigid Bodies

Tags	Summary	Compatibility	Validator
🔑	Assets must contain at least one rigid body	openusd
🔑	Colliding Gprims must apply the Collision API.	openusd
✅	Rigid bodies have to be UsdGeomXformable prims.	openusd	latest+
✅	Rigid bodies cannot be part of a scene graph instance.	openusd	latest+
✅	Rigid bodies can not be nested unless xformOp reset xform stack is used.	openusd	latest+
✅	Rigid bodies have to be UsdGeomXformable prims without skew matrix.	openusd	latest+
✅	If an asset is expected to be static (no movement happens), it can not contain a rigid body, only a Collider body.	openusd
✅	The Mesh Collision API can only be assigned to Mesh Prims.	openusd
✅	The collision shape scale must be uniform for the following geometries: Sphere, Capsule, Cylinder, Cone & Points.	openusd	latest+
💎	Rigid bodies or their descendent collision shapes should have a mass specification.	openusd
💎	Rigid bodies or their descendent collision shapes may have detailed mass properties including density, center of mass, and inertia tensor.	openusd

Joints & Articulations

Tags	Summary	Compatibility	Validator
🔑	Rigid bodies which are not free floating should be connected using joints.	openusd
✅	Targets set to Body0 and Body1 relationships must exist.	openusd	latest+
✅	Body0 and Body1 relationships must not have more than one target.	openusd	latest+
✅	Articulation roots cannot be nested.	openusd	latest+
✅	Articulations are not allowed on kinematic bodies.	openusd	latest+
✅	Articulations are not allowed on static bodies.	openusd	latest+
💎	For stable and fast simulations of kinematic chains, an asset should define an articulation.	openusd

Hierarchy

Hierarchy

Tags	Summary	Compatibility	Validator
🔑	All prims in the hierarchy must be direct or indirect descendents of a single root root prim.	openusd
🔑	Stage must specify a default prim to define the root entry point.	openusd	latest+
🔑	All prims representing objects or groups that require placement, posing or animation shall be xformable.	openusd	Manual
✅	The root prim of a placeable asset shall be an Xformable prim (i.e., a prim that inherits UsdGeomXformable, such as Xform).	openusd
✅	Transformations on prims that are intended to be translated, rotated or scaled by users should conform to the UsdGeomXformCommonAPI.	openusd
✅	For articulated assets without joint definitions, the prim hierarchy should reflect the kinematic chain.	openusd
✅	Geometry should be grouped in a way that is logical for the object’s structure.	openusd	Manual