Cheatsheet: How to get a Cleaner image with SP3

[mrhalaby]

we should probably start another thread with these tricks, where the first post contains all of them?

Anyways, here's my 2 cents

Maybe all of you know this but... when using the same tool in the quad menu again and again, there´s no need to select it all the time from the list, you can click on the quad menu separator. Clicking on the grey area marked in red has the same effect as clicking on the highlighted tool. A few seconds saved.

[Streetwise]

So if my Max subdivs is at 100, and my Color threshold is at .01 and I'm still getting a little too much AA (red), where do I go from there? Is it okay to go up past 100 on Max subdivs?

[padre.ayuso]

So if my Max subdivs is at 100, and my Color threshold is at .01 and I'm still getting a little too much AA (red), where do I go from there? Is it okay to go up past 100 on Max subdivs?

Hey David,
I think if you keep on going with Max Subdivs you are going to get nowhere. You can either bring down the color/noise threshold or you should bring up the Min Subdivs from 1 to 4 or to 6. I have been doing that with no much impact to my rendering times and the noise comes down. To say it is 100% noise free would be wrong, but like Vlado says "some noise does bring in reality". Let me know if that cleans it up a bit.

[timmatron]

My (basic) understanding is that higher subs should get rid of the red, so that seems odd. .01 threshold seems pretty high so maybe try going into double digit zeros. For my renders to get an acceptable low level of noise I am usually between .005 and .001.

[Donfarese]

I'm surprised we can't get something that detects the red and such and auto adjusts the settings for us. I mean we have stuff like auto levels and such, why can't something be programmed to autodetect the colors and adjust for the next render, or even before the render? Vlado good sir?

[^Lele^]

So if my Max subdivs is at 100, and my Color threshold is at .01 and I'm still getting a little too much AA (red), where do I go from there? Is it okay to go up past 100 on Max subdivs?

In theory it is.
Most likely, however, something else is wrong with your scene, and you'd probably be better off checking what exactly is producing visible noise after 60.000 rays per pixel (at defaults.).

[Pixelcon]

And where does MSR fit into this 'new method'? Leave it at default of 6?

[Streetwise]

In theory it is.
Most likely, however, something else is wrong with your scene, and you'd probably be better off checking what exactly is producing visible noise after 60.000 rays per pixel (at defaults.).

It's a 5Kx5K interior scene with a single HDRI light source. So that may be my issue? Currently I'm getting a very clean image overall at .01 and 100 subdivs, but it's looking like a 20hr render, so turning the noise threshold down isn't really an option. I think I'll try what Padre suggested and turn my min subdivs up a bit and see if that helps the AA.

[padre.ayuso]

I'm surprised we can't get something that detects the red and such and auto adjusts the settings for us. I mean we have stuff like auto levels and such, why can't something be programmed to autodetect the colors and adjust for the next render, or even before the render? Vlado good sir?

The only problem with that is that if you want it faster and can do with a noisy image, then you can't stop it? The only thing is that you can essentially do the same with Progressive mode. You can put it so that it renders to its heart content and then stop it when you are happy with it. VRay will keep on making it blue and blue and blue, only working on the red areas, not the blue ones. It works that way too in GPU, it will stop working on the blue areas and refine the red ones. But in Adaptive Mode it is too wide of a request which I personally wouldn't want.

[Streetwise]

Adaptive Mode it is too wide of a request which I personally wouldn't want.

Is that to say that you prefer Progressive mode or RT GPU?

[padre.ayuso]

Not necessarily. But consider if you have one station to render on, say 32 cores, it is not faster than having one or two Titan X rendering. I have tried it. But if you have 6 machines on a server room (which is what I have) plus some extra workstations not being used, I can render a 3K (HD) image in 30 minutes max, which is faster than having two Titan X going (1 to 2 hours depending on the scene). So at the end of the day, I work it by loads on my server machines.

What I meant on "Adaptive Mode is too wide of a request", meaning that having VRay handle noise automatically to make it all blue on its own on Adaptive Mode is too wide of a request, you would never have control over time frames VS noise clean up. But using Progressive or RT GPU you can stop when you hare happy with the result, even if you set it up to render indefinitely until everything is noise free.

Anyhow, in a matter of weeks this should not be a problem with Vlado's denoiser, so I think we should hold it till that comes out. I feel your rendering times will be brought down quite a bit and you will have 5x cleaner images.

Best
Alex

[^Lele^]

And where does MSR fit into this 'new method'? Leave it at default of 6?

It will even go away from the basic settings soon.
Vlado went to some length testing renders with a disparate set of scenes, with varying MSR, and 6 was found to be STATISTICALLY the best.
What that means, in practice, is that in any scene, you may have a chance to get a SLIGHT improvement on rendertime by raising (or lowering) the MSR (even areas, raise, fine texture/geo detail and moblur/DoF, lower.), but that overall the change to the value providing for improvement will be a small window (in our tests, it was NEVER going to get better after 12, or below 3, for example.), and even then, the % difference over an heterogeneous image (your standard production shot) was seriously small (hardly ever up to 10%, in the best of cases.).

Some automagic adaptation already happens (for stuff like fur, for example) and more research is being done on that stuff, so things may change again in the future.

TL,DR: Forget about it, leave it at 6

It's a 5Kx5K interior scene with a single HDRI light source. So that may be my issue?

Your render's made up of shaders on geometry too.
You may have bad geo, wrong shader setups, superfine noises: the list is nearly endless, besides lights.
That's why a scene may be needed to see what's happening, because...

Currently I'm getting a very clean image overall at .01 and 100 subdivs, but it's looking like a 20hr render, so turning the noise threshold down isn't really an option. I think I'll try what Padre suggested and turn my min subdivs up a bit and see if that helps the AA.

...if it isn't clean hitting 70k sp, and it's a "standard interior with an IBL", you REALLY should make sure you aren't forcing V-Ray to oversample through some erroneous setup, before asking it to sample more, just to be sure.
For if that's the case, the issue may also be forcing vray to sample to whatever max AA/msr you'll ask it to, which will definitely not make your renders cleaner, faster.

[Pixelcon]

Cheers Lele. I'll have to re-educate the plebs at work again on Monday

[padre.ayuso]

Your render's made up of shaders on geometry too.
You may have bad geo, wrong shader setups, superfine noises: the list is nearly endless, besides lights.
That's why a scene may be needed to see what's happening,

Actually, there was a scene recently Bobby needed some help on and it was found that the HDRI was trying to go through one small window and was making the scene render with very high times to get a clean image. If that's the case for you, trash the HDRI and try putting a plane on the window. I have been doing that more recently on my interior scenes and it speeds up the render times as well by a great lot of time and hence it improves the quality but not the effect I'm going for. In photography I believe this is called bank lighting? Or something like that.

[^Lele^]

Actually, there was a scene recently Bobby needed some help on and it was found that the HDRI was trying to go through one small window and was making the scene render with very high times to get a clean image. If that's the case for you, trash the HDRI and try putting a plane on the window. I have been doing that more recently on my interior scenes and it speeds up the render times as well by a great lot of time and hence it improves the quality but not the effect I'm going for. In photography I believe this is called bank lighting? Or something like that.

Why not use a light portal then?