Two or more objects in the scene can share the same Object ID.

The Object ID Render Chanel creates selection masks based on Object ID that show each object (by Object ID) in a solid unshaded color.

UI Path: ||V-Ray Node Editor|| > World > Render Channels > Matte > V-Ray Object ID

See the Render Channels page to find out where you can find these properties.

Channel Name – Customizable name for the render channel.

Enable Deep Output – Includes this render element in deep images.