Cycles: huge white dots problem, scene included

[konrad_ha]

Hi everyone,

Cycles brought me back to Blender again. The first impressions are incredibly positive, but now I'v hit the first roadblock:

In the attached image you will see horrible, horrible fireflies (or white dots). It's probably due to the liberal use of a glass material and indirect lighting, but these are just necessities for this scene.



I played with pretty much any setting in the integrator and none had any positive effect on the dots.

I attached the scene so you can try to render it without artifacts.

droplet_011.blend

Blender Version: 2.60.5 r42025 with Cuda support.

Any help is appreciated.

[konrad_ha]

THE SOLUTION:

Some browsing through this forum got me to this thread, describing the source of the fireflies: http://blenderartists.org/forum/show...oise-in-Cycles

They tend to appear when direct light is bounced ONCE off an object and then into the camera, causing a near reflection of the super-bright lightsource.

I adjusted my lightsources accordingly so that direct reflections and refractions would be highly unlikely. I also made my lightsource-objects invisible as lined out in this post: http://blenderartists.org/forum/show...mission-Source

Now I can render the scene without fireflies and with all the lighting I want. See the attached file for the solution.



Also: Cycles is amazing!

[ampace]

Great job, and great tip! Thanks!

[bedamichl]

Thanks for the tip, may have the same problem and will try to fix it!

B.

[JulianLorenz]

There is also another way to fix the problem with the white dots: Just go to renderoptions>integrator and check "No Caustics". In addition there is an option to filter the reflections underneath, but i found it is unnecessary to deal with it....

[patb]

There is also another way to fix the problem with the white dots: Just go to renderoptions>integrator and check "No Caustics". In addition there is an option to filter the reflections underneath, but i found it is unnecessary to deal with it....

Hello, I found another one, which works very well for me (while "no caustics" did not): set Clamp to something more than 0, in the same "Integrator" area. 1, 2, 5, 10, ... you can test it out. 0 means no limit, and this seems to result in speckles.

[abhaya]

I confirm ~patb solution worked out for me.

[liwid]

I just made an eyeball somewhat according to a tutorial,
but when rendering I got a whooole lot of fireflies on the glass material.
I heard about setting the Clamp value to 0.98, but that
completely killed the strength and contrast in the lighting?
Any suggestions how I get the same light effect with the new clamp value?

This is the rendered picture with 1000 samples 100% resolution
http://imgur.com/3wsQdlT
and this is how dull it got with clamp value of 1
http://imgur.com/yaTg9X4

What the fuck

Im completely new to 3D programs so Im sorry if the question is retarded haha..
All help appreciated,
Lisa

[liwid]

Hi, when increasing the clamp value to 0.98 which I heard was good,
the strength and contrast in my lighting completely died!

without clamp:
http://imgur.com/tenfLin,6HMtVwe#1

clamp value of 1
http://imgur.com/tenfLin,6HMtVwe#0

Im sort of new to rendering so I might be retarded, but:
how do I compensate in other settings to keep the contrast while having a clamp value?

All help appreciated
Lisa