Excessive amount of noise

[1=2]

Hello,

We are currently working on a disco club, and spent last day trying to clean up noise in image changing various vray settings. Nothing seems to help.
Scene is fairly complex in terms of lights - uses predominantly mesh lights and several vray light materials. It has several vray lights as well as maing source..
Initially we tried with Irradiance map +Light cache, but after having endless calculations, switched to BF+LC. After 8 hrs of rendering VrayLight passes of all lights are super super noisy in dark areas. They look like big chunks, which is super weird. We tried resetting vray settings, merging into a new scene - same. IM+LC seems to be almost same speed as BF+LC in Progressive mode.
This is not the first time we work on such kind of project and to be honest we did not have any issues several months ago with another and earlier version of Vray 3.2.

You can see the noise in top right corner, almost everywhere there is a mesh light. Image took 13+ hr on single 4930k, whereas similar scene with twice more vray lights (Vray 3.2) took no more than 5 hr.

On a recently completed interior scene we had similar problem- huge amount of noise in white material which was behind glass. Fix it by increasing Min Shading Rate to a big number, but render time increased almost twice.


Has someone else experienced similar issues, or we should delve into the scene more? Unfortunately deadline is knocking on the door.

Thanks in advance!

[werticus]

get rid of mesh lights imo they only cause issues. Replace with vray lights, shaped as planes, spheres, discs etc.

[squintnic]

agree i think there is something wrong with mesh lights - replace with normal lights and it will be much faster.
i use them very sparingly

[1=2]

Thank You all for replies.
We managed to deliver images on time, but turned off the mesh light and used only vray light material only applied to these curved shapes. Noise was still visible after 15 hr of rendering though. Luckily time was on our side.
Later on we did some tests on certain regions and found out that raising MSR to a much higher number like 64, or 128 gave us cleaner image within same amount of time. Especially in GI and Reflections, despite making Light pass a bit noisier.
The drawback was that instead of fast 3 min passes(MSR set to 6 ) we had 30 min per pass(MSR set to 12 in Pogressive rendering mode.
Still not getting really familiar with how to optimize renders only by using MSR, although being long-time Vray user.

[^Lele^]

The light material has a bug in the current release.
There's another topic around where someone was having issues with difficult to clean noise, and Vlado tracked it down to something in the lightmtl.
If you could share (to my chaosgroup email, ofc) a scene, we'd be grateful, anyway.
Mesh lights don't currently have any reported issue, and should work with performance much similar to standard light fixtures (for the same fixture shape and size, of course.).

[anthonyh]

tangent incoming..
honestly i don`t know if it`s particular scenes being awkward but in vrays attempt to become `simpler` it seems to have become much more complicated. trying to get clean images seems to need a phd now where it used to just be a better quality vs time scenario. now you have to juggle the shading rate/noise threshold/aa subdivs etc to see what works per scene. for an example of this you only have to read any thread explaining about how any of these settings work, math all over the shop. i never needed anything but adaptive 1/4 0.005 before, now it`s a bit of a guess what settings work. now i`m probably doing things wrong i totally accept that however vray used to work with me whereas it seems to now only want to work one way (which obviously i`m not be in tune with yet). i`ve seen the `cheat sheet` thread but all the kerfuffle you have to go through with render passes to show samples etc. and again adjust on a `per scene` basis just isn`t workable. in an animation/production environment (at least ours) clients give us no time for any of that. i`m considering downgrading for now to see if it works better for me presuming we still can ? (or whether this is just rose-tinted spectacles). don`t get me wrong, i want vray to be simpler, but i have to be working, not constantly playing with settings. the impression i get is that maybe vray has been improved a lot for still images etc. animation not so much.
anyway don`t want to seem like too much of a rant, scenes misbehaving causing grief that seemed to render fine before and now not are poking me with sticks.
sorry for the diversion, return to your scheduled programming.
anthonyh

[^Lele^]

It would help if you showed us what the problematic scenes are.
The decision to go the way we did was taken to avoid users' mistakes (and god knows there were a LOT of those.) which led to over and undersampling.
The method is by far the strongest V-Ray ever had to get to a clean result regardless of the scene in question.
That users decide we had it all wrong, as we clearly have no clue on how to use V-Ray, and dive in to break what defaults were set is unavoidable, to a degree.
We can only give you tools, and methods, and write time and again the exact same words, but we can't force anyone to read, or do, whatever it is we think best.
Bugs and mistakes do and will always happen, and that is why we take great care in looking at users' scenes and their setups, but you'd be surprised to discover most of the times the pain is well self-inflicted: break defaults, tweak this because i've always done it this way, and do that because i know better. THEN it breaks.

It's not far removed from a car dealer selling you a car, and telling you to use the accelerator to move forward, when the clutch is fully released.
If you think you ought to give that clutch a burn-in because your 10 years old old car needed it, and then burn the clutch, how's that the fault of the dealer?
If, however, you tried PRECISELY what you were told, and THAT doesn't work, then yes, the problem's with the dealer, and you can return the car for checks.

Namely, in your post above, i do not see the issue at all: get the render settings at their default, render (a crop.), if it's noisy, lower NT, if it stays noisy, raise max AA.
Render time will of course vary, and that has ALWAYS been the case.
How did you set up your scenes before, pray tell?
If adding a SR RE is a deal breaker to you, i can't help you there, besides adding it automatically, which has been considered.
Then again, you'd have to go all the way to the drop-down menu at the top of the VFB and change channel.
Which likely would be "keruffly" as well, given your tone above.

Sorry if i sound slightly miffed: i am.
Send me a scene, and then we can have a debate on what is wrong with V-Ray and what is wrong with the User's setup which went against the suggested workflow.
Unsubstantiated, wild, catch-all claims get my blood boiling, but that's no news, hey.

[AlexP]

Its currently the easiest it's ever been. With the denoiser making it even easier.
Just use the default sampling and press render. If it really is still slow/noisy then at least you have a solid base to tweak from.

[anthonyh]

hi again,
no need to panic, you`re not under attack, there`s no `tone` and no wild claims, and i suggested many times it`s the way *i`m* working with vray. internet message are impersonal and easy to see issues where there aren`t any. although you`re analogy of a car dealer telling you what you `should do` and it`s your fault if you don`t is very apt, it was my point too. vray seemed more flexible in the past, at least to *me*(i`ll add that qualifier from now on!), i could mess with the settings `at my peril` and happily live with the results. vray 3 seems more exact in the way i *should* work. my view on this may change once it clicks, who knows.
you`re right in that leaving default settings is the best way and that messing with settings can get you into trouble although i never had any major problem before, there were always little tweaks to help, global subdivs/noise threshold and certain motion blur tweaks etc. that worked better than the defaults nothing ground breaking, they just don`t seem to work any more for *me*. having gotten used to one way of working it`s always a tear to have to change my ways. having barely used brute force/lc before it seems that`s the way it`s going now, not a bad thing since it`s much quicker although not as quick IR which i used mostly. i`m not yet convinced it will be always quicker versus what i could live with before but we`ll see.
as you say, the tools are there but i don`t often have the time to use them all *properly* to achieve deadlines, it`s really just that. denoiser, i`d love to use but it`s another step to add and it all takes time. factor in rerenders galore because of painful clients and every step counts. give me loads of time for every job and i`ll gladly do everything by the book.
once i get more free time i`ll gladly send a troubled scene.
until then shouldn`t be rambling on again since i genuinely don`t want to raise anyone`s blood pressure.
anthonyh

[^Lele^]

No worries about my blood pressure, it's generally kept all too low anyways.
The issues you are facing are the issues we are facing with many old-time users.

Namely, the affection to tweaking which was a requirement for quick renders before 3.3 (everything had decent defaults, on its own, but may or may not have played well in concert with other things).
As of 3.3, DoFed and MoBlurred scenes even tend to render quicker than plain scenes, for a given noise threshold, for example.
Which makes perfect sense, as both effects blur the image, so they lower the local contrast, so the sampler ADAPTS, allowing the sequence to clean faster.
That was impossible (not really impossible, but VERY convoluted to achieve. I know, as i made a movie and a tv series with similar approaches to sampling) before 3.3.

So in a way you are right: there are differences between the defaults of the old V-Ray, and the defaults of the new one, and on how it all works together.
But while you could achieve precisely the behaviour of the old V-Ray with 3.3+, you would be seriously hard pressed to achieve a similar quality in a given time with versions which came before 3.3.

I wrote it in the cheatsheet post, a few times: "Refrain from tweaking".
At least as a first approach to something entirely new, that looks to me like very good application of game theory.
That there may be corner cases in which the new sampler finds it harder than the old approach, we can all agree on.
That each and every user should find those corner cases to be their daily experience, when NO TWEAKING has been done to the settings, i still have to find proof of.
And that's why i keep asking for scenes, and so far i had a grand total of zero cases which had the settings at their defaults, a year and a bit from the cheatsheet post (including the scene which started the thread, non-withstanding the issue with the lightMtl.).

I'm not panicking, i'm not replying here because i feel i am under attack: it's part of my job, and i am genuinely trying to help, which isn't identical to laying down and get two years of hard work of a committed team lambasted and diminished without the shred of a proof about the claims.
That you should read it as a reaction to some personal insecurity of mine is cute, but quite wide of the mark: take a look at the new website, and at the client's work on display there, and you'll see why that isn't the case.

TL, DR : I can help fixing problems, i can't fix unsubstantiated perception.

[anthonyh]

hi,
even when i blame myself i`m still the bad guy. i`ll cut my losses.
thanks
anthonyh
that sounded curt, sorry.

[^Lele^]

I don't see who painted anyone as the bad guy.
I tried explaining precisely, factually, objectively, what the issues are.
Including that of the evanescent perception, when any change happens (it's a very common thing for every living being, really, including me.).

If it sounded harsh, i am sorry, it wasn't so much personal, as generic.
I shall wait for the problematic scenes, for whenever you'll find the time to send me one, so to at least give you back a fix, or a quicker render, in return for the misunderstanding.

[anthonyh]

hi lele,
well i`m working on one scene right now. just trying the `cheat sheet` method. it`s working to a point. using BF it never truly seems to be what i`d call `clean` like what you`d get with the IRmap although trade off is less flicker for animations ? maybe that`s it, i`m use to using IR not BF so it`s naturally more noisy at the start. it`s getting better but i`m not sure i`ll get the IR equivalent clean without heavier render times, the rub is that IR medium/high animation in this scene is not working at all well.
i do understand i`m supposed to use vray 3 differently. i`m trying but probably been resorting to old habits.
i also apologise, messages are easily read as being angry rather than just jotted down without thought about how it`s read the other end. as you say these were only my perceptions of how i`ve used vray in the past. i`m also sure you`ll have a field day with any scene i send, no gamma, no vray frame buffer. i`m gonna get clobbered. it`ll be a slightly truncated scene as it`s client cad. who to send it to ? can`t be public i`m afraid.
anthonyh

[^Lele^]

Eh, yes, the defaults for primary GI are now BF, and again, while counter-intuitive at first, it's by far the best general approach (it will not flicker, or blurb around, regardless of what's thrown at it).
I have written somewhere else (but can't recall where.) on the forums on the benefits of moving away from IRMap, and on how that will require some readjustment of expectations: it may render longer - often not by that much - but it will never be an issue in and of itself - unlike the IRMap -, and it will require zero setup -again, unlike the IRMap - .
It's not that the IRMap is bad, it's just that the times have moved on since its inception, and heyday.
And what i mean by that is that 10 years ago no one dreamt of the average detail a modern scene contains: stuff was broadly composed of flat, even surfaces, and we were all very happy we got some light to shine into that corner.
Today, people add fur to carpets by default, 4k textures on the minutest of detail, and i do not see why they shouldn't.
However, that negates most of the benefits the interpolated approaches provide, by virtue of the fact very little can be interpolated when the detail frequency approximates, or exceeds, that of a pixel (say, fur in the distance.).
There are cases where for a still, or a camera animation sequence, that will work well, and quickly, provided one doesn't really look to close at what the lighting is doing, but the moment one has animated lights and/or geo, the requirements for the IRMap calculation will approach, or exceed, those needed by the BF calculations (that aforementioned fur on a distant carpet, f.e.).

No worries about the misunderstanding, and again sorry for the harsh tone: hit me at emanuele.lecchi at the chaosgroup domain with a scene, and a description of what the issues are, and how you'd like it to behave, and i'll see if i can be of any help (words are cheap. mine all the more so. )

[anthonyh]

hi lele,
i finally had a gap to send you a scene. it`s a bit *gutted* due to client cad. basically IR/LC is 3mins a frame. BF/LC is up to 10-30mins depending how clean you want it. i`d appreciate your thoughts. i tend not to work *by the book*(gamma 2.2 etc) so maybe it`s something obvious ? i`ve also got another problem scene with lots of white trees(just white vray material) exterior shot and under the tree canopy is a haven for noise but i don`t want to overload you. sent via external upload.
thanks
anthonyh