This page provides information on the Material ID Node in V-Ray for Blender.
Overview
This node allows you to assign an ID number to any material in your scene. This ID can be later used to extract a mask for all objects with that material using the MultiMatte render element.
UI Path
||Node Editor|| > Add > Material > Material ID
Node
ID – Sets a unique identification number for that material.
Base Mtl – A slot for the material that the ID will be assigned to.
Material Id Color – Sets color for Material ID.
Parameters
ID – Sets a unique identification number for that material.
