Constant stuck buckets, can't render animation!

[Moriah]

I've been going around this for days, and can't seem to find what's going on. I get random stuck buckets in certain objects with shaders applied, if i include/exclude them in some lights. The problem is that it's a huge animation project and i can't find what's causing this issue. The buckets get stuck forever and the CPU is working 100%. There's loads of alembics, environment, characters, etc. I don't have access to the nightlies even though i already asked for it, but i'm using the latest stable build. Tried others, same issue. Thing is we are using cryptomatte so we cannot go way back to older builds. Also not sure if it has to do with aerialperspective, but we are using the "affect environment rays" to give it a night look.
Stopping the render doesn't work, nor canceling it. I have to force close 3dsmax.exe ...

Here's what i tried:

- Shader override works, but ofc that's no solution
- Aerialperspective gets stuck too
- BF/BF gets stuck too
- GI off gets stuck too
- Embree off gets stuck too
- Bringing in new scene and importing vray settings and objects layer by layer gets stuck too

If i collect everything in the scene if might be a few GB, but i need to fix this ASAP. Any suggestions?

[vlado]

It's hard to say what may be taking the CPU cycles in such a heavy scene. If you can grab several minidump snapshots of the 3ds Max project using Process Explorer and send it to me at vlado@chaosgroup.com I will be able to tell you more.

FYI buckets are not usually stuck; there is usually some very lengthy calculation that needs to be completed. It might some very bright speckle that needs lots of rays to clean up caused by a bright reflection or refraction, a SSS heavy object or something else.

Best regards,
Vlado

[Moriah]

In an act of desperation, i think i found the issue. There were 2 lights in the scene that had the include/exclude in include mode but without any objects in it. I isolated the characters only with those lights in a new scene (without aerialperspective, gi, etc.) only their shaders (skinMtl, sss2) and it got stuck. As soon as i overwrite with a grey shader it renders.

I'll make a few tests in the final scene and report back. If that's the issue i'll send you a scene file with just the characters and those lights. By the way, i'm rendering on a ryzen machine, don't know if that has anything to do with the problem or not, but after many years with vray i'm sure i had several times some lights with the same include without anything in it (even though it doesn't do anything) and never had this problem before, even with a lot more complex shaders.

[Moriah]

Ok, even though it's rendering correctly the entire scene, there's a weird bug on the lighting and specular pass, not on other render elements. I tried setting the cutoff to 0 in all lights, but nothing else comes to mind. All render nodes have the same version, and it happens in all frames. Any idea what's going on? Huge chunks of dark lighting, doesn't seem to be related to anything specific in the scene. It happens with and without characters... And it doesn't show up in the RGB/denoised pass. The comper came back to me and said if this could be fixed, else he cannot use it as it is.

We're using latest vray, forest pack 5.3.4b

[Moriah]

Installed latest forest pack in case it was it, but the same problem persists... Any idea vlado?

[vlado]

Ok, turning off the adaptive lights will probably fix it (set it to "full evaluation"). Obviously we need to fix it on our end, but I will need a scene for that - probably a simplified version will do.

Best regards,
Vlado

[Moriah]

That seemed to work! Thanks! I'll send you a simple scene asap.