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Table of Contents

This page provides information on the USD import and export workflows in V-Ray for Maya.

Starting with V-Ray 6, update 2 the default USD translator becomes Hydra compatible. 


Import Workflow


USD files can be loaded in Maya and rendered with V-Ray using the MayaUSD plugin with mayaUsdProxy nodes.

We recommend following a standard workflow with MayaUSD when rendering with V-Ray. See the video for more.

  • In Maya, go to Create > Universal Scene Description (USD) > Stage From File...
  • Locate the desired USD file in the directory window.
  • Click on Create.



Importing V-Ray materials using USD files


The standard workflow imports V-Ray materials as Maya materials.

  • V-Ray materials that are exported as USD files can be imported into Maya as native V-Ray materials using the mayaUSDImport command.
MEL example
mayaUSDImport -file "/path/to/file.usd" -primPath "/" -shadingMode "vray" "none"

  • Alternatively, there is an interface menu equivalent to the mayaUSDImport command. To import a USD file with native V-Ray materials, go to File > Import. In the pop-up menu, set the File Type to USD Import. Set the Plug-in Configuration to V-Ray.

Click here for UI example


 



Importing V-Ray Physical Cameras using USD files

USD files can be used to import V-Ray Physical Cameras and all their attributes using the mayaUSDImport command. 

MEL example
mayaUSDImport -file"/path/to/file.usd" -primPath "/"

If you are using a zip-installed V-Ray 5, update 2, for Maya or newer, make sure to set up the PXR_PLUGINPATH_NAME environment variable. Otherwise, exporting and importing V-Ray Physical Cameras is impossible. For more information on setting up environment variables, please visit the Installation from zip page.



Export Workflow


  • In the File > Export All Options window, set the File Type to USD Export and choose whether the materials are exported as USD Preview Surface or as V-Ray materials. You can export all materials in the scene as one or multiple types of networks.

    • Alternatively, you can use the V-Ray menu's Export Materials to USD option. For more information, please visit the Export Materials to USD page.

Exporting lights to USD does not require the V-Ray Material Exporter to be selected in the Export to USD menu.

Disable the Merge Transform and Shape Nodes option from the Advanced rollout for a cleaner hierarchy and export. If you are using a version of V-Ray for Maya prior to 6.20.01, the Merge Transform and Shape Nodes option needs to be disabled to correctly export VRaySubdivisions.

When exporting objects with applied V-Ray Displacement, the displacement is exported along with the shaders. In this case, make sure the V-Ray materials option is enabled.

When exporting objects with an applied Subdivision attribute, the subdivision is exported separately from the shaders. In this case, enabling the V-Ray materials option is not mandatory, as it will not affect the export of the subdivision surface.

When exporting objects with applied Subdivision attribute and V-Ray Displacement, the subdivision and displacement are exported along with the shaders. In this case, make sure the V-Ray materials option is enabled.



Working with Multiple UVs

Starting with V-Ray 6, update 2 the default USD translator is Hydra compatible.

Export and import of multiple UVs is supported under the following condition: digits are forbidden as first characters in the name of the UVset.

To ensure proper workflow with UV sets the export Plug-in configuration should be set to V-Ray. Otherwise, they are exported with Maya's convention.

Should unexpected errors occur using older assets, it is recommended to re-export the UVset.