More tipps to prevent noise in interior scenes ?

(Alain) #1


I tried to follow, understand and do the tricks from here and from other users like for example Negativa:

But do not achieve a good resolut.
I need a noisefree image a HD-resolution (1920x1080px).
Even after 3000 Samples it is to noisy.
See here:

You can download a light-version of the scene here:

Does anyone know how to get a noisefree image at lower samples ?
I appreciate any tipps :slight_smile:

Kind regards

(eppo) #2

Sun energy - 1
World AO - 0.3, dist - 6
Render Sampling Clamp - .95

Hope helps a bit.

(Alain) #3

Thanks for the tipps eppo.

Unfortunately it doesn’t help mutch :-/
Increasing Sampling Clamp makes a rendering noisier.
Enabling AO makes a rendering very “grayish/colorless” and flat.

See this comparison:

Does anybody else know how to prevent noise as mutch as possible ?

Kind regards

(mik.a.) #4

This is not a method to prevent noise, but to reduce after rendering: when doing noisy scenes i prefer (for now, waiting cycles progress :))to do instead of one single render at 3000 samples, two renders at 1500 samples with different seed and ‘merge’ them in one image with something like (in gimp) darken only or mix 50% .

(Alain) #5

Thanks mik.

This method only helps a little, little bit :-/

See below:

Any other suggestions ?
Or any good experiances with some noisereductions postproduction tools ?

Kind regards

(mib2berlin) #6

Hi Alain, try to change your glas material to portal (switch of ray visibility > Camera).
I try to render this scene with octane and it is very hard to render.
At the end I render 2000 samples pathtracing and 1000 samples direkt lightning and mix it in blender compositor.

Maybe it help a little, mib.

(sundialsvc4) #7

Definitely don’t overlook the BI render and “ambient light.”

Interior scenes which have dull lighting and soft, pastel colors are difficult to produce, in my experience, because (I hypothesize …) the algorithm is trying to converge on a solution and there simply isn’t that much difference; not that much that is truly distinct. Not much to cleanly converge upon.

Cycles IMHO is “a great photographic soft-box.” It will give you a good, even, indirect lighting solution in a reasonable amount of time. But if the solution does not converge in 100 iterations it’s not more likely to converge in fifty times that number. Look upon it as “just one” source of data that you can potentially tap into.

(Alain) #8

I’m not sure if I understood you right:
When I turn off the ray visibility for the glass then I don’t see the glass anymore (reflections get lost).
So what is it useful for ?

I tried the scene in Octane as well, and fighting against noise is about the same in Cycles and Octane.

Sorry I don’t understand what exactly you wanna tell me :slight_smile:
Can you give some visual examples ?

Kind regards

(mib2berlin) #9

If you replace the glass with the portal material from layer 3, you lost reflections but render clears up much faster.
I think the most people don´t see it anyway but this is only fake.

Cheers, mib.
EDIT: I try also with helper mesh emitter behind the camera with low emission ~ 0.2
Test render with 600 samples with mesh emitter, portals.

(Alain) #10


Thanks for your effort.

Why you place a mesh emitter behind the camera ? It’s like a flashlight of the camera ? Is it to light up the room a bit more ? How does it influence the “noise” ?
Why there are some rainbow-colors by the windows ?

The goal is to do an interior animation and I don’t wanna lose the reflections on the glass because it doesn’t look real.

Are there some points in the doto-featurelist of Cycles which improve the “noise-problem” of interiors ?
I can’t find any “Exitportal”-Material in this todo-list but maybe there are some other points which do the same but I don’t understand them ?

Kind regards

(bob:granch) #11

Maybe good hdri lighting will help you.
For me it gives better results.

(Alain) #12

In my experiences HDRI’s produce more Fireflies/noise than just a Skytexture-Node.

Kind regards

(negativa) #13

For the final render using 2000-3000 samples.
Take a good look set of objects and materials.

Unfortunately I do not have time to explain what tricks I use, so carefully review the file!

(mib2berlin) #14

Hi Alain, the glass material you use is a “portal” material. It is more effective as emitter only.
I uploaded the edited blend, the things I change are:
Area lamps deleted > mesh emiter.
Added 2 big mesh emitter, one back camera, one in the roof (to get more rays “photons”).
@negativa, this is no offense but I don´t understand your setup, it is much slower than the original file and produce fireflies on lower samples.
Maybe you have time to explain an other day, :slight_smile: and may Alain can use some of both files.

Cheers, mib.
EDIT: Alain you can use

(bob:granch) #15

I try to render blend file but can’t see textures - images are not visible in the UV Editor.

To Alain
Maybe not a big problem but… This is Skechap model. Right? (… or AutoCAD?)

I recreate the Skechap models, because there are strange “effects” when render (… before I worked with AutoCAD and 3dsmax +vray).

Really interesting setup.

(Alain) #16

Thank you alot guys !

Negativas tricks convince me the most :wink:
Using AO in the rawrendering definitily makes a rendering “flat” and unrealisitic.
I guess only using AO as a Pass could help to get more depth into a rendering in Compositing.

See comparison:

Download my Scenefile and you will find the textures that are missing mib2berlin’s file.
I don’t have a problem with Sketchup-Modells, I love Sketchup because it keeps my head free with technical nonsence :smiley:

Kind regards

(eppo) #17

Some theory questions i have, looking at this problem.

You do have cylinder with applied sky texture imitating visible through window picture and light coming (FOR THE INSIDE SHOT) from out through window openings - Portals (whatever that might be), which actually is light source for your scene. Great. And i wont go over that while you move camera inside, window view will change just slightly…
At the same time software dealing with render task is plain stupid (i wont believe if you tell me different) and will go crazy trying to light, shadow, texture, represent, occlude and what not OUTSIDE of your model grabbing for that valuable CPU cycles.
Am i right assuming this?
Can we eliminate that?
Can we concentrate all effort and available resources only on inside calculations?

This model was for 100% percent imported in blender from another modeling software. See naming, texturing details in outliner. Fine.
For a still image meant to be rendered in Cycles which will build BVH tree once to get known whats behind what, where to shoot photons and such. That shall take time, CPU cycles, tenths of seconds. Not so significant if it is one still image but will make a huge impact if it is one frame of 1000 and geometry is complex, like in this.

Therefore, do we need to eliminate all not needed geometry if we plan on image sequence, how to find/consider what’s not needed?

For example, wall behind the camera - there will be just some twice or 3 times bounced light rays hitting camera from that; or better yet knowing that rays for now are shot from camera to scene…

Do we still need to keep that wall in scene and make calculations for this?

Any authorities out there, any comments, please!

(eppo) #18

Using AO in the rawrendering definitily makes a rendering “flat” and unrealisitic

Really dunno… If you hit T while at render result in uv editor, there’s that nice color curve adjustment gadget.
Again taste differs and i otherwise probably would not… Have you looked at image link i did put? That did not look monotone pale or really, did it? It’s still noisy, 250 samples only, true.