Hi, I'm trying to isolate contributions from individual lights using the lpe tags. I've added the LPE Tag (vm_lpetag) render property to my light and set it to, e.g. “key”, then I've added an extra render var in my Karma LOP with the LPE “CD<L.'key'>” but I just get a black image. Switching to the LPE to “CDL” gets me just the direct diffuse contribution (for all lights) so the output itself is working.

Hi. The existing LPE tag properties are for mantra only. There's currently no way to specify tags for Karma at the moment.

Ahhh good to know, thanks. On a similar note I can't seem to get Karma to output an albedo/color pass. Is there a special variable name (using the principled shader) for that or is it not supported?

As long as the shader has the VEX export, you can write it to an AOV. Principled/classic shader exports basecolor as “export_basecolor”, so in your karma or karma render properties LOP, create a new “Extra Render Var”, set it to “color3f” format, and set as “Source Name” as “export_basecolor”. (without quotes)