Problem: sandstructure very noisy in animation

[Dirk71]

Hi together,
I'm trying to render a little camflight over a beachscene with a very fine sandstructure.
The problem is that the noise (sand) flickers like hell. I'm using the irradiance-prepass/
rendering-preset because there will be moving objects in the scene too. But how do I
avoid this flickering? Can anyone tell me?

I've attached a little testanimation and some screenshots of my rendersettings.

Best regards,

Dirk

here is the animation:

http://www.file-upload.net/download-...stani.zip.html

[RErender]

You don't show your AA settings so hard to say if those are the issue but i would guess it is, that or the subdivs in the sand material if your are using glossy reflections. Your DMC noise threshold is also pretty high at .01 depending on your settings I sually have it down at .006

[Dirk71]

oops, I uploaded the wrong screenshot. Here are the other settings:

[RErender]

The material?

[Dirk71]

the material glossy-subdivisions are at 32

[RErender]

ok, that should be enough subs on the glossies, are you using a bump or displacement? If it is a bump maybe try lowering it a bit, I'd also try a lower DMC threshold, You might try overriding the color threshold of the AA to .005-.006.

Could also be over bright areas, in that case try turning on sub pixel and clamp output in the color mapping, also try making your lights invisible.

[Kyle_Grace]

Have you tried a different AA filter? I think Sharpening filters may cause flickering on details such as this.

[Dirk71]

First of all, thanks a lot for your tips.
Ok, using your settings reduces the noise flickering enormous but not totally. The flickering
is still there and my rendertimes quadrupled with the new settings. At the moment I´m trying
to render a short sequence, without glossies in the sandmaterial. Its about 20 Minutes per
frame now ;-(

[Dirk71]

@kyle
in the new test I`m trying simple area. What would you suggest?

[Joost Ink]

@kyle
in the new test I`m trying Mitchell-Netravali. What would you suggest?

quadratic or area would be my best bet.

[^Lele^]

If you use area, you might try up the pixel size for the filter to something big, like 4.

[Dirk71]

At the moment I´m testing a bruteforce/lc method. with the use of the area filter it seems to work fine so far
and the rendertimes are much better now. thanks a lot for the help.

[Kyle_Grace]

Quadratic or area would be where I'd start. Because there's lots of fine colour variation, I think you might actually need a blurry AA filter in order to minimise the noise. Give it a try and let us know how you get on.

- sorry, didn't see that you'd already solved the issue. Got involved with photoshop and forgot to hit 'post'.

[vlado]

It might be a problem of the very fine details in the texture map... does it flicker if you turn off the sand texture?

Best regards,
Vlado

[Dirk71]

No, it flickers only when the sandmat is on, it´s definately the fine structure.
After a lot of tests with irradiance and different AA settings maps I´ve chosen the "Universal V-Ray 1.5 settings"

http://www.spot3d.com/vray/help/150S...nisettings.htm

This works best at the moment.

...Btw the area filter is at 1.5 in the last test