V-Ray for SketchUp
Masks
This page provides information about the V-Ray Masks.
Last updated 1 September 2026
This page provides information about the V-Ray Masks.
Overview
The V-Ray Masks are used to refine only selected parts of the rendered image in the VFB. They can be applied to Color correction layers, Lens Effects, the Denoiser, Folders and also to Render Elements (when the Source layer is set to Composite) in the VFB layers tree.
V-Ray Mask can be created using the Add layer button. The same option is available in the right-click context menu of the layer tree under the New layer category. There's also a quick Mask creation button in the Properties area of folders and layers.
When one or more masks are applied to a folder or layer, a mask icon is placed in front of it in the layer tree to signify its presence. The parameters of each mask are available in their own separate tabs to the Properties of the masked layer or folder.
The masked areas are defined by selection of objects, materials, groups, layers, etc. To specify them, respective Render Elements must be available in the rendered image. Currently, there are three Mask types: Integer Mask, MultiMatte Mask, and Cryptomatte Mask.
UI Path:
||V-Ray Frame Buffer|| > Layers > Select layer or folder > Add button
||V-Ray Frame Buffer|| > Layers > Select layer or folder > right-click menu New Layer option
||V-Ray Frame Buffer|| > Layers > Select layer or folder > Properties > Add new mask layer button

Parameters
The following parameters are common for all masks:
Blending – Determines how multiple masks are blended together over a single correction layer:
Overwrite – Sets the current mask as it is, without blending it with the masks before it (standing on its left).
Add – Adds the current mask to the result of all masks before it. This is the default mode.
Subtract – Subtracts the mask from the result of all masks before it.
Multiply – Multiplies the mask with the result of all masks before it.
Divide – Divides the mask by the result of all masks before it.
Element – Specifies the render element from which the mask is read. Only render elements available in the rendered image and compatible with the type of the mask are listed in the dropdown.
Opacity – (Mask opacity multiplier) Determines to what degree the selected layer obscures or reveals the layer beneath it. Even if there’s only one mask child, you can modify its opacity. The opacity is multiplied by the mask color.
Show preview when selected – When enabled, shows a preview of the mask if the mask is selected.
Invert mask – When enabled, inverts the mask results.

– Аdds a new mask layer.

– Shows all tabs of the currently selected color correction layer.

MultiMatte Mask
The MultiMatte Mask is based on the MultiMatte Render Element.
Use red – Uses the red channel as a grayscale mask.
Use green – Uses the green channel as a grayscale mask.
Use blue – Uses the blue channel as a grayscale mask.
Use intensity – Uses the pixel intensity as a grayscale mask.

Integer Mask
The Integer Mask is used with Render ID and Object ID Render Elements.
+/- Pick – Adds/removes items by picking them from the Render View. When activated and the mouse is inside the Render View, a red square indicates where the value is exactly picked.
Clear all – Clears all items from the item list.
New item – Allows you to type a mask ID manually and then add it to the current selection with the + button.
+ – Adds IDs to the list.
- – Removes IDs from the list.

Cryptomatte Mask
The Cryptomatte Mask is based on the V-Ray Cryptomatte Render Element.
+/- Pick – Adds/removes items by picking them from the Render View. When activated and the mouse is inside the Render View, a red square indicates where the value is exactly picked.
Clear all – Clears all items from the item list.
New item – Allows you to type a mask ID and add it to the current selection with the + button. The text is case insensitive.
+ – Adds IDs to the list.
- – Removes IDs from the list.

Drag and drop masks to another layer to move or copy them.
