VRayLighting and VRayRawLighting RE'smissing IES lights

[dlparisi]

It seems like IES lights aren't being picked up by the VrayRawLighting or VrayLighitng RE's. Here's a simple scene, just a box, an IES light and a camera:

RGB:


VrayRawLighting and Vray Lighting RE (both are all black - was this even necessary to post?):


Weirdly the IES does show in the VrayTotalLighting RE but not the VrayGlobalIlumination RE(so where is it getting the IES light info from?):


I noticed this since a BacktoBeauty composite wasn't matching in another scene but I was able to workaround it by replacing the Lighting and GI RE's with just a TotalLighting RE.

So...am I missing something or do I have something tagged wrong?

Scene attached (substitute any ies file for the missing one as it doesn't seem to make a difference). Vray 6.20.02/max 2020
RE's missing IES light.zip

[dlparisi]

I've now noticed that the IES light seems to be missing from the VraySpecular RE as well. If you add some reflection to the walls the IES light doesn't show up in the RE (I think it should, right). Incidentally, it's not in the VrayReflection RE either but I think that's the intended behavior. Regardless, the BacktoBeauty composite does not match to the stock RGB. I can't seem to get a workaround for this since the IES doesn't show up anywhere else.

[hermit.crab]

Hm. This is a weird one. I am reproducing the issue but without any consistency - the Lighting/RawLighting REs are sometimes present and sometimes not. I am not yet sure exactly what's happening. I'll continue testing and write back.

[hermit.crab]

Well, the issue happens on a fresh scene, but still without any consistency. Sometimes just rendering a few times makes it pop. FYI, I've logged it (internal bug-tracker id: VMAX-13856) for dev investigation.

[dlparisi]

I can get the ies to show in the rawlighting RE but not the regular lighting RE. If I have the sample scene from above and I remove all of the RE's then load up just Lighting and RawLighting, the RawLighting will have the light but the regular Lighting pass is still black. If I then add a DiffuseFilter pass the RawLighting goes black again. Same thing if I add a LightingAnalysis pass (there are probably others but this is where I stopped testing). Hope this helps.

[hermit.crab]

I can get the ies to show in the rawlighting RE but not the regular lighting RE. If I have the sample scene from above and I remove all of the RE's then load up just Lighting and RawLighting, the RawLighting will have the light but the regular Lighting pass is still black. If I then add a DiffuseFilter pass the RawLighting goes black again. Same thing if I add a LightingAnalysis pass (there are probably others but this is where I stopped testing). Hope this helps.

This also seems inconsistent and most likely linked to the original issue. The elements sometimes do appear as they should. I'll add the info to the report.

[dlparisi]

It's not a workaround, but the IES shows up in all REs when you switch the GI engine to irradiance map. Maybe something that could point to where the problem is.

[dlparisi]

Similarly, if I leave the Primary GI as Irradiance map but change the secondary to Brute force, the IES vanishes from the REs. More clues...