Requirements#

Warning

This feature is currently a work in progress.

What is a requirement?#

A requirement is a specific condition that must be met for an asset to be considered valid.

A requirement may contain attributes as:

A code to identify the requirement.
A message to display when the requirement is not met.
A path to a documentation page that explains the requirement.
A compatibility tag that indicates the requirement is only relevant to certain use cases.

Requirements may contain more information in the future.

What is a capability?#

A capability is a collection of requirements. It is used to group requirements that are related to a specific feature.

Where are requirements defined?#

Requirements need to conform to the contract omni.asset_validator.Requirement defined in omni.asset_validator. As such, any class conforming to this contract can be used as a requirement.

In particular, requirements in Asset Validator are defined in the omni.capabilities module. We will use it in the following examples.

Adding requirements to your validation rules#

To add requirements to your validation rules, you can use the register_requirement decorator. Here’s an example:

import omni.capabilities as cap
from omni.asset_validator import register_requirement, BaseRuleChecker

@register_requirement(cap.GeometryRequirements.VG_001)
class CustomRule(BaseRuleChecker):
    def __init__(self, parameters):
        super().__init__(parameters)

To report an issue, for example with the AddFailedCheck method, you can use the following code:

self._AddFailedCheck(
    requirement=cap.GeometryRequirements.VG_001,
    at=source,
)

The requirement will automatically fill in attributes such as the message, path, and compatibility tag. To override these attributes, you can set them manually, for example to change the message:

self._AddFailedCheck(
    requirement=cap.GeometryRequirements.VG_001,
    at=source,
    message="Custom message",
)

Requirements#

Code	Message	Rule
AA.002	Asset must use only supported file types	`SupportedFileTypesChecker`
AA.001	Asset references should use anchored paths	`AnchoredAssetPathsChecker`
AA.OV.001	Texture UDIMs are not supported in USDZ files in NVIDIA Omniverse	`UsdzUdimLimitationChecker`
AA.003	Asset paths should use forward slashes for cross-platform portability	`PortableAssetPathChecker`
UN.001	Stage must specify upAxis to define the orientation of the stage	`StageMetadataChecker`
UN.002	Stage must specify metersPerUnit to define the linear unit scale	`StageMetadataChecker`
VG.002	Boundable geometry primitives should have valid extent values.	`ExtentsChecker`
VG.010	Do not subdivide meshes with Normals.	`SubdivisionSchemeChecker`
VG.007	Mesh geometry must be manifold	`ManifoldChecker`
VG.009	Use indexed primvars when values are repeated	`IndexedPrimvarChecker`
VG.018	Mesh topology should be without unused vertices, edges, or faces.	`UnusedMeshTopologyChecker`
VG.019	Faces should have non-zero area.	`ZeroAreaFaceChecker`
VG.016	Each vertex position should be unique	`WeldChecker`
VG.014	Mesh topology must be valid	`ValidateTopologyChecker`
VG.011	Only include primvars that are actively used	`UnusedPrimvarChecker`
VG.027	All non-subdivided meshes must have normals.	`NormalsExistChecker`
VG.028	Mesh normals values must be valid to produce correct shading.	`NormalsValidChecker`
VG.029	The winding order of faces in a mesh must correctly represent the orientation (front/back) of the face.	`NormalsWindingsChecker`
VG.MESH.001	All geometry shall be represented as non-subdivided mesh primitives using the UsdGeomMesh schema.	`_ContainsMeshChecker`
VG.025	Geometry shall be defined as such that the asset is correctly positioned and oriented at the origin (0,0,0).	`_AssetOriginPositioningChecker`
HI.004	Stage must specify a default prim to define the root entry point.	`DefaultPrimChecker`
VM.MDL.001	MDL material source assets must be properly referenced and accessible to ensure material loading and rendering.	`MaterialPathChecker`
VM.BIND.001	Material bindings must use appropriate scope to ensure proper material assignment and inheritance.	`MaterialOutOfScopeChecker`
VM.PS.001	Material attributes must comply with the UsdPreviewSurface specification to ensure consistent rendering and viewer compatibility.	`MaterialUsdPreviewSurfaceChecker`
VM.MDL.002	MDL Shaders must standard OpenUSD shader source attributes to ensure compatibility.	`MaterialOldMdlSchemaChecker`
RB.005	Rigid bodies cannot be part of a scene graph instance.	`RigidBodyChecker`
RB.003	Rigid bodies have to be UsdGeomXformable prims.	`RigidBodyChecker`
RB.009	Rigid bodies have to be UsdGeomXformable prims without skew matrix.	`RigidBodyChecker`
RB.COL.004	The collision shape scale must be uniform for the following geometries: Sphere, Capsule, Cylinder, Cone & Points.	`ColliderChecker`
JT.002	Targets set to Body0 and Body1 relationships must exist.	`PhysicsJointChecker`
JT.003	Body0 and Body1 relationships must not have more than one target.	`PhysicsJointChecker`
JT.ART.002	Articulation roots cannot be nested.	`ArticulationChecker`
JT.ART.004	Articulations are not allowed on static bodies.	`ArticulationChecker`
RB.007	Rigid bodies _or_ their descendent collision shapes should have a mass & their other inertial properties explicitly specified.	`MassChecker`
HI.001	Prim hierarchy must have a single root prim.	`_HierarchyHasRootChecker`
HI.003	The root prim of the asset hierarchy must be transformable	`_RootPrimXformableChecker`
VG.RTX.001	World space bounds must not exceed RTX limit.	`AlmostExtremeExtentChecker`
VG.020	The values of the points attribute must not exceed the limit at which a given precision can be represented using 32-bit floats.	`PointsPrecisionChecker`
UN.006	Stage must specify upAxis = “Z” to define the orientation of the stage	`_UpAxisZChecker`
UN.007	Stage must specify metersPerUnit = 1.0 to define the linear unit scale	`_UnitsInMetersChecker`