This page provides information on the Object ID Render Element which isolates individual objects with different colors based on IDs for compositing purposes.
UI Path: ||Render Settings window|| > Render Elements tab > Object ID
The parameters for this render element appear in the Attribute Editor under Extra V-Ray Attributes.
Enabled – When enabled, the render element appears in the V-Ray frame buffer.
Deep output – Specifies whether to include this render element in deep images.
Filename suffix – The text added to the end of the rendered file, when saved as a separate file (e.g. myrender.objectID.vrimg).
The 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.
Object ID Render Element
Matte created in composite by using only the red channel
Original beauty render
Glow and brightening added to the composite using matte created from
Object ID Render Element red channel (as a mask in composite)
Select the geometry that an Object ID Render Element is needed for.
Add the Object ID attribute Attributes > VRay > Object ID while the shape node is active for the geometry.
Set the Object ID to the required value. Note: each number corresponds to a different color.
Open Render Settings and go to the Render Elements tab and from the Available render elements add an Object ID render element.