This page provides information about Material ID Color Render Element in V-Ray for SketchUp.
Material ID Color render element creates a mask based on the material ID Color parameter. To add the render element, you first need to add Material ID attribute from the Add Attribute button ( ) to the material.
Opacity color and textures are supported by the Material ID Color channel.
This render channel is useful in a compositing process as a color mask for different materials in the scene.
How to Set Material ID Color
After you add a Material ID attribute to the material, an automatic Material ID Color is set, but you can change it from the Asset Editor and select the preferred ID Color.