Reducing Cycles SSS Noise

How can I reduce the graininess in SSS shader for the candles I have in this scene? I’ve been working on this for several days, and no matter what render settings I try, it still looks terrible. I’ve tried more light bounces, I’ve tried less. Basically, if it’s a setting in the render settings, I’ve messed with it somehow to try and fix this. Is there something with lightpasses I’m missing? And is there a way I can improve the fire material (Fire2 in the .blend) I’m using?

Thank you.

Sorry i’m not into dl’ing files except images, but to find the default settings just open a new instance of Blender.

To get rid of noise at the cost of accuracy look at Clamp in Sampling and Filter Glossy in Light Paths.

If your candle lights are (encased) within some kind of transparent medium then you may want to split the scene into layers and render separately and put back together in post processing.

They’re not encased and the default settings make so much noise and fireflies it’s not even funny. I’m rendering using Progressive Refine at the moment to see if that makes any difference. Using Blender 2.69, by the way.

Have you turned on multi importance sampling for your lights?
okay you have.
Metaballs is taking a while. consider converting them to meshes.

8K samples is a lot. crank that way down for your test renders.

You are getting fireflies because your lights are too dim. Turn up that emission.

Anytime you put a light path node in it’s going to cost you in render time.

Before going any further

Remove the duplicate geometry of one of the candles (overlapping)
Apply scale and rotation to the objects in the scene
Reduce the high subdiv settings on the objects for testing
Use only a single candle for testing

Now try various settings to reduce noise

Update: Progressive rendering didn’t help.

@DruBan: I’ll try turning up the emission now.

@pappy: I’ve created a new .blend for testing. I noticed my geometry got screwed up somewhere, but I wasn’t sure where.

New test .blend:

I’ve simplified the geometry (cylinders only) for testing purposes. Also, I’ve more than doubled the light pass emission shader (was 90, now 200). And I’ve created multiple “candles”, moved them to layer 2, but kept one on layers 1 and 2.

Any suggestions for the number of bounces? I’m at 512 now. Been playing around with it to no avail. Too high? Too low?

Thank you guys SO much for your help so far.

Holy Bartender, Batman! I figured it out! You guys TOTALLY have to check this out. It should fix any firefly issues in any render. Make sure to pass this info on, as I will. It’ll save others a TON of time and frustration.

“If you’re unfamiliar with High Dynamic Range (HDR) lighting, basically it stores high-precision RGB (red, blue, and green) values for each pixel, so unlike most image formats, which store RGB values from 0 to 255 (as that is the greatest range of details you’ll find in screens currently), HDR formats store values from 0.0000000 to 1.0000000. This is what Blender uses internally.
Cycles, as noted here, likes to return values greater than 1.000. If you look at fireflies’ color values in Blender’s image editor, you’ll notice just how extremely overblown they are — some have values greater than 100!
So you figure you’ll just clip it at 1.000 and be done with fireflies forever, right? Well, not so fast… Cycles may sometimes return values greater than 1.000 for some non-firefly pixels, so you’ll need to experiment with your own scenes as to what cut-off value would be best. Usually anywhere from 1.0 to 2.0 will serve your scene well and exclude fireflies from your renders.”

Thank you for everyone’s suggestions. You guys are so cool for even reading, much less responding. Keep Blendering and Cycling!

And Merry Christmas!

One more quick question, and it’s prolly dumb, but I gotta ask anyway:

How do I mark this thread solved?

Thanks, guys!

Actually, I do have one more quick question. Is there a way to make the SSS shader look smoother? When I render, the candle wax SSS shader still looks grainy. The fireflies are gone, though.

Thank you!

Any suggestions for the number of bounces?

Yes, way to high.
Try with Direct Light in Integrator Presets.
Enable No Caustic and Filter Glossy in file 2.

There is something with your materials wood/wall, start with simple mix diffuse/glossy materials.

SSS is slow in every render engine (except Arnold :slight_smile: ).

Cheers, mib.

Did you try the branched path tracing? I get normaly less noise for the same amount of render time for SSS. Also you can set more sampes for SSS only.
If I can remember well the new SSS shader is optimised for branched path tracing and was extreamly noisy with normal path tracing. Brecht fixed that but it coud be that its still noisier than branched.