how to render lights and fog without noise?

[miohn]

Hi,

Happy New Year first to all of you!

I have massive problems to render a scene (some cars in the night/fog which are lightning
an object with their headlights)

I tried with PT and PMC with 16.000 samples/ 1.000.000 light samples but its still noisy as hell.
I'm using an Environment sky with scattering medium Volume step length set to 0.2

Any tips for getting fog and visible lights rendered clean would be very nice!

thanks
Mike

Need to precise my post a little bit.
The extrem noise only occures when working with area-ies lights and
whatever settings I try - I cannot get rid of that noise.
Tried with volume-object, fog in environment sky and also the classic "cube" method.

When I only use an hdri environment or sun I get the scene with 512 samples noisefree in seconds.

So how to deal with arealights/IES-Lights inside volumes toi get them clean?
Or is there another better method to generate car headlines?

thanks
MIke

[bepeg4d]

Hi Mike,
the IES light is behind a specular material?
Can you share the scene or a simple version with only lights with geometry?
ciao beppe

[miohn]

Hi Beppe,

here is the example. (without hdri and textures)

Test_Fog_Car.zip

(4.96 MiB) Downloaded 373 times

Got a bit better result without the other cars/lights (carmodel was free - I hope ),
but in the end I need about 6 or 8 cars around lightning the cube in the middle.

Tried with the headlight-glass and without, but in terms of accuracy there should be glass I think.

Maybe you can have a look at the scene and could give me some tips.
As said, with an hdri or sun only fog renders absultely clean.
But anyway - I need these headlights.

thanks
Mike

[bepeg4d]

Hi Mike,
here is my attempt:

Test_Fog_Car_b.zip

(4.9 MiB) Downloaded 712 times

basically, I have reduced all the emitting options at more natural values, and unticked the "Cast illumination" option at yours emitter materials, in this way the original lights are still visible to the Post effect without producing noise.
Then I have created a small plane emitter moved out to avoid recessed light paths.
I have changed the temperature at 12000 for better see the effect.
You have to place all the other instances, and fine tune your settings.
You still need to render at higher sampling level but now should be far less noisy.
ciao beppe

[miohn]

thanks very much beppe!

I will investigate your scene and compare to my previous settings.
This will help me definitely further!

thanks
Mike