This page provides information on the V-Ray Object ID Render Channel which isolates individual objects with different colors based on IDs for compositing purposes.
Overview
The V-Ray Object ID Render Channel isolates individual objects with colors or integer values for compositing purposes.
Parameter
The parameters for this render channel appear in the Parameters tab under the out Network and within the render elements node.
Name – The text added to the end of the rendered file, when saved as a separate file (e.g. myrender.Object_ID.vrimg).
Deep Output – Specifies whether to include this render element in deep images.
Common Uses
The V-Ray Object ID Render Element is useful for isolating geometry in a scene based on the Object ID. This means that items can be isolated by use of a matte, created from the solid colors within the Object ID pass. This method is used to isolate and color correct the ottoman in the example. The ottoman has an Object ID of 1, the floor has an Object ID of 4 and the walls have an Object ID of 2. See how the render looks before and after compositing.
Notes
The name of the Object ID render element must consist of the name of the Object ID itself, a dot and then any other string to be properly read in Nuke. For example, VRayObjectID.example. Do not include numbers in the name.