About noise in general

[PIXELBOX_SRO]

Hi Bertrandt,
i dont think Solidrocks will work there.....i used solidrocks in similar scenes and it gave me nothing but light leaks even though it was set to ultra settings (i mean the plug is nice but it doesnt do magic)

* have you tried merging all the stuff into a new scene and setup vray from scratch?? i dont know why but it sometimes helps
* its quite hard scene for the sampling....the light has to travel quite far to make all the bounces....maybe its just because of the scenes nature??? Alhtough i have to say its madness to achieve such times at this resolution.
* strip the scene from all the nice bits, leave just the lighting, pute pure white material and post the download link here...i am sure we could all find the way hot to make it work ))
* i know this will not help you, but myself, i am not really overjoyed with the vray 2.0 functionality (please dont kill me guys for saying this) + plus i really miss some explanations in vray manual ...simple descriptions of functions are not really helpful

[BBB3]

Thanks Martin,
I think I'll do that. I'll just pack the scene without textures and furniture, see if I still get the same problem, and post it for anyone who doesn't mind spending the time to have a look.

[bardo]

what are your hardware specs? Did you use only a pc ?

Just to have something to compare.

[BBB3]

Yes, just one workstation with eight cores and 16GB of RAM.

[pixela]

Hi Bertrand,
I was thinking the same things as Bardo and although I read that you need all the glass, I want to tell that I have a strange issue with the glass in the interior I am working on.
When I hide glass, noise disappears. When I turn on glass, I get some noise and a strange bluish cast in the GI which I didnt understand where comes from (glass has no tint in diffuse, reflection or fog color)
Moreover, the objects behind glass get more saturated or darker.
I really don't know if I am making a mistake somewhere or missing something- and can be my mistake but this made me think if there is any problem with refraction.
I made numerous tests too. And cant find what I am missing.
So I know you need the glass to be there but does your problem disappear when there is no glass?

[BBB3]

Thanks for the input, Pixela. I haven't tried to render without the glass but I will as soon as I finish my current project (deadline looming).
I also have had weird behaviour in my glass (diffuse = pure black, refraction = pure white) when using fog colour. Bizarrely, when rendering this scene in RT, some parts of the glass come out a very dark, saturated green. Only in RT though. But in the production renderer, some glass panes cast darker shadows than others. I checked all the normals and they are ok. Very strange.
It's an interesting suggestion, though, so I guess the next thing I'll do is try one render without glass.

[Neilg]

But in the production renderer, some glass panes cast darker shadows than others. I checked all the normals and they are ok. Very strange.

I see this happen randomly between different computers. (and through the workstations at 2 jobs...) It's like different installs of vray convert the units wrong and ramp it way up.
Sent a scene to vlado, but he cant replicate it.

[pixela]

Thanks for the input, Pixela. I haven't tried to render without the glass but I will as soon as I finish my current project (deadline looming).
I also have had weird behaviour in my glass (diffuse = pure black, refraction = pure white) when using fog colour. Bizarrely, when rendering this scene in RT, some parts of the glass come out a very dark, saturated green. Only in RT though. But in the production renderer, some glass panes cast darker shadows than others. I checked all the normals and they are ok. Very strange.
It's an interesting suggestion, though, so I guess the next thing I'll do is try one render without glass.

Let me know your results when you make the tests.
As I told in previous post, all can be my mistake but I can't locate where the mistake is.

About noise in interiors: Another thing I noticed was the noise on glossy reflections. They render extremely noisy and I need to increase subdivisions very much to see without noise-free.

[CA Portugal]

This glass issue happened to me too today. I had a black car behind a glass with several panels. Everything seemed fine but in one of those panels, it seems like the car didnt have any glass in front of it.
Also while rendering outside of the glass store, with many cars with dif colors (white, grey and almost pure black) inside of it, all cars looked GREY, almost equal to each other. My glass is also pure black diffuse, pure white in reflections. No fog.

Jacinto

[BBB3]

Well, I seem to have resolved part of the problem. First of all, when rendering the scene without any glass I got a very noticeable reduction in noise. This doesn't help me, though, because I need all this glass here. I then removed all fog colour, which is a shame but something I can live with, and got the noise to hit an acceptable level that way. It also got rid of the strange shadow artefacts I was getting in RT.
Mostly, however, the problem seems to have come from my own approach. It seems I was following the wrong noise-busting strategy. As Rivoli suggested, I tried to lower the AA settings, both the threshold and the subdivs, and to put pretty much all of a burden on the Brute Force subdivs and noise threshold. By raising the subdivs to 60, I could get rid of 80 per cent of the noise and hit a relatively reasonable render time. It doesn't look like this would ever be a fast scene to render, but at least I can get it clean. I'll post some images of my tests in the next few days if anyone is interested.

[rivoli]

glad to hear you're getting close to solve this one, it does look like a tough one, but it's a beautiful scene already.
don't know if you tried that already, but maybe setting the glass objects to not receive and cast shadows may help with the noise as well. if it does you can have the best of both worlds, the glass and no noise

[bardo]

good tips rivoli about shadows glass.

When I have clear glass, I always turn off shadows and often I turn off also the "generate GI" into vray properties

[BBB3]

I haven't tried blocking the shadows. That's a good point although I like the way the shadows get progressively darker when the light crosses two or more panes (I haven't checked if it still does that without the fog colour though).
I tried deactivating "generate GI" for the glass but somehow it made the scene much darker...

[bardo]

Sorry... I've checked, it's not "generate GI" but "visibile to GI".

[rikou]

ok, it seem you're close to solve your problems, it's cool but I would be very curious to know why there is some problems with Vray 2.0 about noise we didn't have with Vray 1.5. This puzzles me a lot...
Anyway, I always desactivated "generate GI" for the glass but kept turn on shadows. I will try to reactivate GI (never saw the fact that the scene was much darker...)
And of course, it's always a real pleasure to see your works ! thanks for all yours sharings, tips and comments