multimatte element not linear?

[jstrob]

With latest stable vray 3.40.02, my multimatte elements are not rendering like before it seems. When I bring them in after effects they are paler and not pure red, green and blue.

is there anything that could cause this in the render settings?

[^Lele^]

do they look correct in the VFB?
If so, how are you saving them out?

[jstrob]

Hi Lele, thanks for your reply!

No they did not look correct in the vfb.

I am using RPManager.

I noticed it was doing this only when rendering with DR locally and then saving using the button at the top of the VFB. When I launched the render on the farm with RPM and deadline, the multimatte were perfect (in that case RPM and deadline take car of saving the files so I don't know the difference with savong from the vray vfb???).

So probably a problem with RPM. I think RPM needs acom^plete overhaul to take account of the new changes in vray... I don't know...

[^Lele^]

ah!
Would you mind trying without RPM (if it's any easy to remove/take out of the equation, ofc.)?
I tried, and on a simple test had no issue, but have no RPM either...

[jstrob]

Ok yes I will try later (after I finish this job) but I also have to test wihtout rpm for another problem: my denoiser element are always black on the farm.

[^Lele^]

I personally always stayed away from RPM since the early days, preferring to write my own pass makers...

[jstrob]

But RPM has so many features I would need to spend years to write all those tools from scratch. It's incredibly powerful and I just can't imagine using max on a production without it. But at the same time it just adds itself to the infinite batch of plugins needed by max that makes it become a huge Babel tower.

[jstrob]

I just made a simple test from scratch and it's outputting correctly... So I must have somthing in my scene creating this... I noticed the result has each 3 pure color but they are not at 1, they are at 0.3591. So red is (0.3591, 0, 0) If up the level in comp to get 1, I get artifacts at the edge of my mask when I add an out of focus filter ofr example.

Also I kind of removed RPM from the equation in my problematic scene by just launching the render with the 3ds max interface and it gives the same wrong result. But when I submit with rpm to the farm it gives the correct result.

[jstrob]

Oups! I just found it!

I had the exposure lowered in the vray frame buffer correction controls... Since I normally never save from the frame buffer I didn't know the correction control effect were saved when using the top button...

It's because I use DR to render a single frame for that job so I launch the render locally.

I think it's a bit weird that the channels like multimatte element, zdepth even DR bucket are corrected when we use the correction controls...

[Morne]

I think it's a bit weird that the channels like multimatte element, zdepth........corrected when we use the correction controls...

Yes this has been mentioned a couple of times. I wonder if something will be done about it or not. Last I remembered there was a discussion if it should or shouldnt be corrected. I can't remember what the outcome of that discussion was, but I feel it shouldnt be

[jstrob]

but I feel it shouldnt be

Hi Morne!

Can you tell me one case for example of why you would want those channels to be corrected when saved by the VFB?

[Morne]

Hi Morne!

Can you tell me one case for example of why you would want those channels to be corrected when saved by the VFB?

Hi!
I think you misunderstood me. I feel they should NOT be corrected in ANY case

[jstrob]

Ok sorry Morne! Now i understand!

[gfa2]

I agree that the VFB adjustments shouldn't modify things like multimatte. We are looking for pure red, green & blue with those elements regardless of adjustment we want to make to the main image. Can we at least have an option for it to affect multimatte or not?

[tashko.zashev]

I agree that the VFB adjustments shouldn't modify things like multimatte. We are looking for pure red, green & blue with those elements regardless of adjustment we want to make to the main image. Can we at least have an option for it to affect multimatte or not?

Yes, we will fix that, but can't promise that it will be done for the next V-Ray update. We will post here when we have any news.