The Self Illumination Render Element isolates self-illuminated materials, including V-Ray Mesh Lights, objects with the VRayLightMtl, and any objects with Self-Illumination enabled in their V-Ray material. This render element is useful for brightening or color-correcting self-illuminated materials in the final composite.
For example, the material VRayMtl has a parameter for self-illumination. If this parameter is set to a non-black color value, this render element will show the results of the self-illumination.
To use render elements, select from the Available render elements column and click the Add button to add the passes you wish to generate at render time. When you render the scene, the added render elements listed in the column on the right, will also render, which can be viewed from the VFB window's channel drop-down menu.
For more information on the parameters on this dialog, see the Render Elements tab page.
