How to render out Phoenix fire on its own?

[sean_brown]

How would I go about rendering out just the fire from a Phoenix sim and all the reflections and light it emits on the surrounding objects on its own pass so that I can composite it separately? In an example i have a ball on fire on a plane. I just want to render out the fire and the light its casting on the plane. Is that possible? Is its certain combo of AOV's and Render Layers? If so, that's where I'm a bit lost.

[hermit.crab]

You can get the fire itself by adding either a VRaySelfIllumination or/and VRayAtmosphere RE. Check this tutorial. However, extracting only the generated light via i.e. a VRayLightSelect is not fully supported yet (internal bug-tracker id: PHI-4872). There is some missing info, but you could try it.