Interiors noise and exterior brightness

[Lewis]

Hi!

I'm posting this in LW section since i use LW plugin version but i don't think it's LW specific but more Octane in general so anyone is welcome to chime in .

Basically i find it very hard to render clean interior in octane if there is not a lot of additional light sources/sky and big openings. I have scene that even on 10 000 samples is very very noisy with Path Tracing.

But looking through gallery i often see very bright (blown out) exteriors and good interior but i want to be able to see sky/exterior through windows and still have decent light amount inside so i wonder what do you use to solve Exposition/Fstop/Gamma for interiors ?

Anyone have any suggestion of his Rendertarget settings/setup that works best for interiors which don't have large windows on all sides of room ?

Here is one 10k samples test which already takes too much time (20 min on 3*780 OC) and it's still way way too noisy and generally not contrasty enough. Windows are behind camera and right from the camera an di used Octane SKY environment at evening (7PM Summer solstice) and played a lot with exposure/gamma/fstop but nothing gives me crisp contrasty results and bright interior . It's either too dark or too noisy.

Camera Imager settings for this are:
Exposure - 0.8
FStop - 2.4
ISO - 200
Gamma 2.2

SKY
19h
Turbidity - 3.0
Power - 0.5
Sun size - 3.0

Thanks in advance

[BorisGoreta]

For this kind of light sources you should use PMC which is designed to clear the light noise much faster.

[Lewis]

Thanks Boris. Yes i've tried PMC and it's better, sadly it still needs about 25k samples to get closer to somethign acceptable .

[gordonrobb]

Wow, that is incredibly noisy.

[CANDITO]

Hello Lewis,

maybe the noise is due to the use of small lights
to light your scene.
I had the same problem recently with a very narrow and long store,
i had to put some rectangular emitters unseen by camera (not to much bright) to
get rid of the noise at around 2k samples. (i used Path tracing)
I usually put them half way between the ceiling and the floor and it does the job...

Oliv

[gristle]

I've found light/emitter proximity to other surfaces can make a difference, especially with extra fireflys.
The scene was even tighter than yours - aircraft interior.

I did the same as Candito mentioned, large low intensity rectangular emitters unseen by camera.

[Lewis]

Hello Lewis,

maybe the noise is due to the use of small lights
to light your scene.
I had the same problem recently with a very narrow and long store,
i had to put some rectangular emitters unseen by camera (not to much bright) to
get rid of the noise at around 2k samples. (i used Path tracing)
I usually put them half way between the ceiling and the floor and it does the job...

Oliv

Thanks for response.

By rectangural emmiters do you mean somethign like large fil lights with small intensity ?

[CANDITO]

Yes, one or two large emitting rectangles
but beware of the reflecting ground.
You could use a rectangle volume, with the top side emitting towards
the ceiling and the downside with a very neutral color, to avoid
too obvious reflections.

Oliv

[Builtdown]

Hi,
Do you have bump maps on noisy surfaces? I have found that bump causes most noise in most cases.

[Lewis]

Hi,
Do you have bump maps on noisy surfaces? I have found that bump causes most noise in most cases.

Yes on some i have but then i need to have them so it can look better/more realistic .

Eventually I've settled on 15000 samples PMC, PT coudln't solve it, Diffuse is not good looking enough.