I am trying to render RGB matte in AOV for further compositing. Can anyone pls explain me how to get this.

Example for Mantra:
1. Create Bind node in your material
2. Set type to “Color” and export to “Always”
3. Set color and name parameters
4. Add new plane to “ROP / mantra node / Images / Extra Image Planes” with VEX Variable like name of your bind node

Thank you very much for the details. I got little confused but I got another video tute of your description.thanks for the project file because without it I wound't have understand the whole thing