USD Export options

The USD export options appear when you select File > Export and choose USD Export in the Files of type drop-down menu. The following options appear under the File Type Specific Options section, letting you select what is included when you export your file. .usd , .usdc, and .usda are supported file formats for export. Exporting from Maya to USD is limited to one scene to one USD file.

Note: mayaUsdPlugin.mll must be loaded in the Plug-in Manager (Windows > Settings/Preferences > Plug-in Manager) for USD Export to appear in the Files of type drop-down menu.

File-Type Specific Options

If you have a plug-in loaded into Maya and it has export options registered and configured with MayaUSD, the following dropdown option appears:

Plug-in Configurations: Select a loaded plug-in configuration to modify your export options. You can choose from Arnold or V-Ray as example configration setting templates to use.

Output

.usd File Format

Lets you select from the following export formats:

Binary (Default): If you select this option, your exported file uses the file extension .usdc and is in binary format.
ASCII: If you select this option, your exported file uses the file extension .usda and is in ASCII format.

Note: Manually entering a file name with an extension .usdc or .usda overrides the selection in the drop-down menu (.usdz is not supported). When a file extension is not specified, USD defaults to using the .usd extension with the binary format.

Create USD Parent Scope

Name of the USD scope that is the parent of the exported data. For example, if the string "salad" is entered, the following code is included in the USD file:

#usda 1.0
(
    defaultPrim = "salad"
    metersPerUnit = 0.01
    upAxis = "Y"
)
def Scope "salad" (
    kind = "component"
)

Geometry

Subdivision Method

Exports the selected subdivision method as a USD uniform attribute. Attributes that are uniform appear with the "uniform" modifier in any layer that contains a properly-authored opinion for the attribute. You can select from the following options:

Catmull-Clark (Default): If selected, the exported file contains no additional code.
Bilinear: If selected, every mesh prim in the exported file is assigned the attribute uniform token subdivisionScheme = "bilinear"
Loop: If selected, every mesh prim in the exported file is assigned the attribute uniform token subdivisionScheme = "loop"
None (Polygonal Mesh): If selected, every mesh prim in the exported file is assigned the attribute uniform token subdivisionScheme = "none"

Note: If you are familiar with scipting in USD, staticSingleSample flag is available on export, which optimizes the conversion of attributes with single time samples to static values. This is especially useful for common mesh attributes as they have the benefit of reducing the complexity of the USD, especially for USD file readers. For example, this will benefit round-tripping USD files into Maya since point-cached meshes will be able to import their UVs if they are static.

Related Concepts: See attribute and variability in the Pixar USD Glossary.

Component Tags

If selected, component tags get exported as USDGeomSubsets. Note: Edges and vertices are unsupported in USD.

NURBS Curves

If selected, curves get exported to USD primTypes NurbsCurves or BasisCurves.

Color Sets

If selected, exports Maya color sets as USD primvars. Primvar stands for "primitive variable". A primvar is a special attribute that a renderer associates with a geometric primitive, and can vary (interpolate) the value of the attribute over the surface/volume of the primitive. When this option is turned on, color sets are written out as primvars:(colorSetName) and primvars:(colorSetName):indices in the exported file.

Related Concepts: See primvars in the Pixar USD Glossary.

UV Sets

If selected, exports Maya UV Sets as USD primvars. When on, UV sets are written out as primvars:st and primvars:st:indices in the exported file. When there are multiple primvars, the index is appended to st, st1, st2, st3 etc. All UV names with custom metadata attached to the primvar can be expected to roundtrip (through import and export) seamlessly. Indexing will preserve on import and material override generation will only occur when necessary.

Skeletons

Exports Maya joints as part of a USD skeleton. By default this setting is toggled to None. If you want to enable the export of joints, choose between All (to automaticaly create SkelRoots in your USD file) or Only under SkelRoots (to have an explicit selection of SkelRoots).

Skin Clusters

Exports Maya skin clusters as part of a USD skeleton. By default this setting is toggled to None. If you want to enable the export of skin clusters, choose between All (to automaticaly create SkelRoots in your USD file) or Only under SkelRoots (to have an explicit selection of SkelRoots).

BlendShapes

If selected, exports Maya Blend Shapes as USD blendShapes. Note: This toggle requires Skeletons to be exported as well.

Display Colors

If selected, exports the diffuse color of the geometry’s bound shader as a displayColor primvar on the USD mesh.

Materials

Select the material(s) to bind to prims for export. With USD, you can bind multiple materials to prims. You can select from the following options:

USD Preview Surface: Shading data to be extracted and mapped to a UsdPreviewSurface Maya shader node.

Note: The UsdPreviewSurface shader node is identical to the pxrUsdPreviewSurface shader node provided by previous versions of the Maya USD plug-in. There may be backward compatibility issues with scenes that have both shader nodes loaded. For more information and a workaround, see USD Limitations in the Release Notes topic for your version of Maya USD).

Related Concepts: For more information, see PreviewSurface in the Pixar USD documentation.
RenderMan for Maya: Exports the authored Maya shading networks, applying the same translations applied rfm shaders to the shader types.
MaterialX shading: Exports bound shaders as a MaterialX UsdShade network.

Note: If you have the Maya to Hydra plug-in installed and loaded (Windows > Settings/Preferences > Plug-in Manager > mtoh.mll), you will get an additional legacy exporter which exports to UsdPreviewSurface using the mtoh codebase. This does not support phong and standardSurface and shows up as mtoh in the drop-down menu.

Texture File Paths

Choose whether your texture files are written as relative or absolute paths as you export them to USD. If you select Automatic, it will be chosen for you in the exported USD file based on what they currently are as Maya data.

Tip: If you have MayaUSD and no LookdevX loaded, it is impossible to create a texture on a prim. You need LookdevX to do this. However, if you open a USD file with a texture already authored, you can change the texture to a relative path using the file browser in the Attribute Editor. For example, you can add a texture on a rectLight or DomeLight prim relatively or even add a non-image file such as a media file on a SpacialAudio prim or a Maya file on a MayaReference prim. To do this, click on the folder icon in the Attribute Editor of a file input you want to make relative and then toggle on

Make Path Relative to Edit Target Layer Directory.

Animation

Animation Data

If selected (default), animation data will be exported as USD time samples. The following option appears when Animation data is enabled:

Frame Range Start/End: Sets the first and last frame of animation to export.

Tip: Click Use Animation Range to automatically populate the Frame Range Start/End fields with the scene's current frame range.
Frame Step: Specifies the increment between time sample frames during animation export. For example, a Frame Step value of 0.5 exports frames 1.0, 1.5, 2.0, 2.5, etc.
Frame Sample : Specifies the value(s) used to multi-sample time frames during animation export. Multiple values separated by a space (-0.1 0.2) are supported. This setting can be used to help prevent interpolation errors.
Euler Filter: Exports the euler angle filtering that was performed in Maya.
Static Single Sample: Converts animated values with a single time sample to be static instead.

Advanced

Visibility

If selected (default), exports Maya's visibility attributes as USD metadata. If the object is hidden in Maya, then the following metadata is included in the export visibility = invisible.

Instances

Lets you export instances by choosing from the following options:

Convert to USD Instanceable References (Default): Exports Maya instances as USD instanceable references.
Flatten: Instances are flattened.

Merge Transform and Shape Nodes

If selected (default), merges transform and shape nodes into a single USD xform prim.

Include Namespaces

If selected (default), namespaces are exported to the USD file in the following format: nameSpaceExample_pPlatonic1. When off, namespaces are removed from the USD file.

Worldspace Roots

If selected, exports the root prims with their worldspace transform instead of their local transform.