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Table of Contents

This page outlines the usage of the built-in migration scripts for legacy scenes.



Some legacy options or features are deprecated and not fully compatible with the latest version of V-Ray. The portal options for lights and the Linear Workflow option (previously found in the Color Mapping settings) are no longer compatible with V-Ray.

V-Ray will detect if a scene uses these features and offer to automatically migrate the scene to a compatible V-Ray setup.

You can select to not be prompted on scene open and instead run the migration manually from the V-Ray menu > Tools > Migrate Legacy Scenes.

The sections below explain in more detail what legacy features can be migrated and what the migration scripts do.



Don't Show This Message Again On Scene Open – V-Ray will detect if opening an old scene contains any legacy features that can be migrated to a compatible setup. In this case, you will be prompted to run the migration. If you choose not to be prompted on scene open, you can manually run the migration from the V-Ray menu > Tools > Migrate Legacy Scenes.

Apply – Runs the migration for all legacy features.

Close – Closes the prompt window without running the migration.




Light Portals

The portal options for lights are not compatible with many new features like Adaptive Lights and Light Mix.

The legacy Light Portal migration will replace Portal Lights with the Adaptive Dome and make sure that Light Cache is used for GI and the Adaptive Lights option is enabled. This ensures faster and more accurate IBL lighting.

The migration script will roughly do the following:

  • Disable all lights that have the Skylight Portal or Simple Skylight Portal option enabled.
  • Look for a Dome Light in the scene and if one is not found, a new one will be created and set to invisible, so as to not interfere with the alpha of the rendered image.
  • If the existing Dome Light does not use a texture, the script will look at the color or texture used as environment override and assign it to the Dome Light.
  • In case a new Dome Light needs to be created, the environment color or texture will be assigned to it.
  • Finally, the migration script will make sure that the Dome Adaptive option is enabled, Light Cache is used for GI and Adaptive Lights are enabled.


Linear Workflow

Historically, the legacy Linear Workflow option provided a one-click workflow for proper gamma correction of textures. However, Maya comes with an advanced and powerful Color Management System that is more capable than the Linear Workflow option to ensure proper correction of input textures against multiple color spaces and is the recommended approach.

The legacy Linear Workflow migration script will disable the Linear Workflow option and add a gammaCorrect node with the appropriate value to all material inputs that need to be corrected.

This ensures that the scene will render exactly the same after the migration.

The migration script will do the following:

  • Disable the Linear Workflow option in the V-Ray render settings.
  • Look at the Gamma value in the V-Ray Color Mapping options. The reverse of this value (1/value) will be used to correct material inputs where needed. For example, 1/2.2 will add a gammaCorrect node with a value of 0.4545.
  • Add gammaCorrect nodes to all inputs affected by the legacy Linear Workflow option:
    • VRayCarPaintMtl
      • Base Color
    • VRayMtl
      • Diffuse Color
      • Reflection Color
      • Refraction Color
      • Translucency Color
    • VRayToonMtl
      • DiffuseColor
      • Reflection Color
      • Refraction Color
      • Translucency Color
    • VRayFastSSS2
      • Diffuse Color
        • VRayFastSSS2 has its own Linear Workflow option. If it is enabled, the diffuse texture input needs to be corrected twice
      • Overall Color
      • Specular Color
      • Scatter Radius Color
      • Sub-surface Color
  • The script will also process the Diffuse Amount, Reflection Amount and Refraction Amount parameters of VRayMtl and VRayToonMtl.
    • The value or texture used for any of the Amount parameters will be multiplied by the respective Color parameter with a multiplyDivide node before the gammaCorrect node.



The migration script will attempt to convert the scene from both legacy features. In case just one feature is used, only that part of the script will be executed.

V-Ray will display a message if the migration is successful.