3ds max - gpu - Multimatte issues.

[Gro]

Being a bit of a fan of MultiMatteElement (not sure if there is a workaround for the following things?) there's a couple of issues I still notice on gpu that seem frustrating...

i) GPU MultiMatteElement is effected by camera vignetting? Shouldn't be. (Can been seen below.)

ii) On cpu if I pass an object id through refraction that is effecting 'all channels' this effecting all channels works for MultiMatteElement, but on gpu this doesn't work. Is there a workaround?



iii) MultiMatteElement Object id 0 shows up black - on cpu this will be coloured (blue above). Ironically this is how the VrayObjectID render element works too ... not only this but for both gpu and cpu I'm not sure what it is doing when it's 0/black - unless there's some utility to this kind of 'null' state that I'm not getting?

[hermit.crab]

1. Thanks for the report. I've logged the issue (internal bug-tracker id: VGPU-5660) for developer investigation. No easy workaround, I'm afraid - you may either render the Multimatte in a separate rendering or apply the vignetting effect in post-production.
2. Refer to this post here.
3. From what I tested, Object ID 0 shows black on both CPU and GPU - it is simply a lack of id hence nothing is returned.

[Gro]

Thanks.

https://docs.chaos.com/display/VMAX/...orted+Features

1. Vignette should be disabled when choosing v-ray gpu, or noted not to work with GPU - can't have vignette effecting other render elements. If anyone just swaps a scene to gpu this effectively just breaks the render elements. They can't just fix that in post if they don't notice, whereas you basically can just add a vignette in post to fix your render after the fact.
2. This post is just more of the same... I think both myself and CLF73 would like a eta or at least a bug number? Without it multimatte support should be asterisked as a supported feature in the above documentation since it won't work with refraction. ... As keen as I am on v-ray seems to be unfortunately taking years for basic production features to be supported. It was already a bit of workaround to add reflections in composition on cpu, with gpu we can't even isolate the refraction STILL, after... 5+ years? I know we're still waiting for out of core for about the same time... I know there's probably competing priorities such as optimization over features, but these kind of considerations would really help v-ray attractiveness to smaller scale productions. Anyway, little rant over - please assure me someone thinks this is actually an issue?
3. Yes for objectID but not Multimatte ... Multimatte on cpu has no problem taking object id 0 and treating it as an object id number. Therefore gpu multimatte should behave the same? 3ds precedence is to treat id 0 as an id number? So if, you want, perhaps this is 2 bugs i) a bug with gpu multimatte AND ii) a bug with both cpu and gpu object id ... Unless you're saying v-ray doesn't follow precedence and v-ray cpu multimatte is actually broken? Although I'm not sure what the utility of this would be (please do correct me if there is a use)? Sorry to be picky; but I certainly don't think it's behaving as expected?

[hermit.crab]

1. It's simply a bug and we should resolve it as soon as possible.
2. We are aware of the issue, however, it's not as trivial to implement, hence I cannot provide a specific time frame. The issue's ID: VGPU-826.
3. Ah, now I understand. The ID "0" is reserved for the background, infinity, or for places where there aren't objects with IDs different than 0. It works in CPU because of the integrated version of V-Ray in 3ds Max (all other integrations require an export to .vrscene).