% WARNING: THIS FILE IS GENERATED BY genSchemaDocs. DO NOT EDIT. % Generated: 03:26PM on February 19, 2026

(OpenVDBAsset)=

OpenVDBAsset

A Field representing an OpenVDB volume grid. See the OpenVDB website for more information on OpenVDB.

An example OpenVDBAsset referencing a single density field in a .vdb file:

def OpenVDBAsset "densityVDB"
{
    token fieldDataType = "float"
    int fieldIndex.timeSamples = {
        10: 0,
    }
    token fieldName = "density"
    asset filePath.timeSamples = {
        10: @/vdb_test_data/grids.vdb@,
    }
}

The filePath attribute must specify a file in the OpenVDB (.vdb) format on disk.

:depth: 2
:local:
:backlinks: none

(OpenVDBAsset_properties)=

Properties

(OpenVDBAsset_fieldClass)=

fieldClass

USD type: token

Represents the class of an individual grid. This attribute is optional.

This is a mapping to OpenVDB's openvdb::GridClass where the values are GRID_LEVEL_SET, GRID_FOG_VOLUME, GRID_STAGGERED, and GRID_UNKNOWN.

(OpenVDBAsset_inheritedproperties_VolumeFieldAsset)=

Inherited Properties ({ref}VolumeFieldAsset)

(OpenVDBAsset_fieldDataType)=

fieldDataType

USD type: token

The data type of a field, such as "float".

Use this attribute to tell consumers more about the field without requiring the consumer access the asset file directly. The list of allowed tokens reflects the available choices for OpenVDB volumes.

(OpenVDBAsset_fieldIndex)=

fieldIndex

USD type: int

The index of a field within a VolumeFieldAsset asset file. This attribute is optional.

An asset file can contain multiple fields with the same name. This optional attribute is an index used to disambiguate between multiple fields with the same name. For example, in an OpenVDB file asset, there might be two Grids named "density". A fieldIndex of 0 would specify that this Field refers to the first "density" Grid.

(OpenVDBAsset_fieldName)=

fieldName

USD type: token

Represents the name of an individual field within a VolumeFieldAsset asset file.

A VolumeFieldAsset file asset may contain multiple fields in a single asset file. This attribute specifies the name of field within the asset file. For example, an OpenVDB file asset might have multiple named Grids, such as "density", "temperature", etc. fieldName would specify one of the named Grids in the OpenVDB file asset.

Note that a Volume also provides a way to specify the "name" for a field, via the field relationship. This name is not associated with asset data and is used by the Volume for organizing fields for the rendering pipeline. See {ref}usdVol_understanding_fieldname for more details on how the field's relationship name differs from fieldName.

(OpenVDBAsset_filePath)=

filePath

USD type: asset

An asset path attribute that points to a file on disk.

The asset pointed to by filePath must be a file type that the VolumeFieldAsset-derived schema supports. For example, for OpenVDBAsset, the file type must be an OpenVDB (.vdb) file. For Field3DAsset, the file type must be a Field3D (.f3d) file.

This attribute's value can be animated over time, as most volume asset formats represent just a single timeSample of a volume. However, it does not, at this time, support any pattern substitutions like "$F".

See {ref}usdVol_using_animated_field_data for an example of using filePath to refer to animated volumetric data.

(OpenVDBAsset_vectorDataRoleHint)=

vectorDataRoleHint

USD type: token

Fallback value: None

Specifies the role of a vector valued field, such as "Color". This can drive the data type in which fields are made available in a renderer or whether the vector values are to be transformed. This attribute is optional.

This token can drive the data type in which fields are made available in a renderer or whether the vector values are to be transformed. Allowed tokens include None, Point, Normal, Vector, and Color.

(OpenVDBAsset_inheritedproperties_Xformable)=

Inherited Properties ({ref}Xformable)

(OpenVDBAsset_xformOpOrder)=

xformOpOrder

USD type: token[]

(OpenVDBAsset_inheritedproperties_Imageable)=

Inherited Properties ({ref}Imageable)

(OpenVDBAsset_proxyPrim)=

proxyPrim

USD type: rel (relationship)

(OpenVDBAsset_purpose)=

purpose

USD type: token

Fallback value: default

(OpenVDBAsset_visibility)=

visibility

USD type: token

Fallback value: inherited