Light select for non-emitting lights...

[Njen]

I've come across a scenario that I'm having trouble working with. I have a number of lamps in a scene, and to help speed up the render, instead of using the actual complex filament geometry to light the scene, I am using a simple corona light. So I apply a CoronaLightMtl to the filament geo and turn off 'Emit Light', so it shows up in the beauty but doesn't cast light. All of this looks good in the beauty pass.

However, when setting up my LightSelect AOV's, it appears that a non-emitting light material will only show up in the 'Rest (unassigned)' set. There is no way for me to properly build an exact beauty pass using all of the light select AOV's if I have non-emitting light materials.

I understand the technical reasons why a non-emitting light material should not appear in a ligh select AOV, however there still needs to be a solution to the problem of not being able to recreate the beauty pass from only using light select AOV's.

Or am I missing something?

[Tanakov]

I tryed few options to help you out, but so far I think its best is to mask the thing out, use the Corona Light as you are, but at the same time use CoronaMask adding the filament and then using that in post.

"rest" does not save as any format other than part of cxr. 
If you have bilion TB's of space avalable try that > Save as CXR > Batch it to save "rest"

But since your light emiters will be 1 max 2 colors deep mask should do the trick.

[Njen]

I understand all of those options, but I don't want to render out another pass if I can help it (thousands of extra frames), and I don't/can't want to use cxr,'s as I am comping in Nuke and using Deadline to render.

[maru]

We are aware that this is an inconvenience, and we've already received many similar reports, but right now the behavior that we have is intended.

We have a task "rethink rest (unassigned" in LightMix" in our internal tracker, so it will be tackled at some point, but for now I cannot provide any specific timeframe. I have just bumped our devs, and will let you know if there are any news about this.

[Njen]

Thank you for your update, it's good to know that not only are you aware of the issue, that you are already tracking it.

Maybe I can do some sort of ID mask AOV of just the filaments that I can use to mask the 'Emission' AOV in comp to get what I need for now in a single render.
Thanks!