Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] I need help! => Topic started by: BigAl3D on 2021-11-26, 16:40:42

Title: Get Rid of Fireflies in Animation
Post by: BigAl3D on 2021-11-26, 16:40:42
I love Corona, but damn if I can't avoid fireflies to save my life. I will upload a scene after I post this. As you can see in this clip, I have fireflies all over the place. I will admit, on the first clip with all the trucks, I had some old chrome materials that were set to 999 IOR reflection. I fixed all of them and you can see in the single truck test, I still have fireflies in many other areas that have much less reflection. I'm assuming reflection is the main cause, but I'm only guessing. The full truck shot is using a simple Physical Sky with basic settings.

The full shot used 15 passes with High Quality Denoising. I also tried Noise Level limit of 5, 4 and 3 with either no change or even more fireflies. Clearly, adding more passes isn't the solution as far as I can tell. The step below the door of the truck is really bad. Upon closer inspection, I'm guessing the source of the fireflies there is the pill-shaped bumps, which are actual meshes and not Displacement.

I'm open to all suggestions.

Cinema 4D r20
MacOS 10.15.7 Catalina
Corona v7 Hotfix2

Title: Re: Get Rid of Fireflies in Animation
Post by: BigAl3D on 2021-11-26, 16:43:36
File name of upload:  Firefly Problem.zip

Had to use Dropbox. The normal uploader just hangs and takes too long, so the Captcha expires. Tried this in two different browsers.
Title: Re: Get Rid of Fireflies in Animation
Post by: burnin on 2021-11-27, 00:55:34
Render settings / Corona >
/Frame buffer  set.

on an 'Image filter' there's a Highlight Clamping option - set it wisely ;)
Title: Re: Get Rid of Fireflies in Animation
Post by: BigAl3D on 2021-11-27, 03:54:12
Oh my God. In my initial test, this worked! I also read in the help that I should be using the Tent setting for Image Filter set to 2. Mine was set to High Quality. I set the Highlight Clamping to 2 and so far it seems to have worked. I'll render the full lot again and report back.
Title: Re: Get Rid of Fireflies in Animation
Post by: lollolo on 2021-11-27, 13:45:52
Have you tried Intel or Nvidia denoiser?
They can handle fireflies much better than Corona denoiser. So I would give them a try.

My choice is Intel. It outperformed Corona in all of my tests.
Title: Re: Get Rid of Fireflies in Animation
Post by: BigAl3D on 2021-11-27, 15:27:17
@Lollolo Interesting. I haven't played much with those. I'm stuck with AMD GPUs so I guess it will have to be the Intel. I'll test it out for speed anyway. Right now the clamping seems to do the trick for fireflies.
Title: Re: Get Rid of Fireflies in Animation
Post by: BigAl3D on 2021-11-28, 17:19:33
Here's the latest render utilizing the Highlight Clamping setting set to 2.

Title: Re: Get Rid of Fireflies in Animation
Post by: Anthe.cr3 on 2021-11-29, 20:42:43
Looks very clean to me!

What hardware are you using, and how long did each frame render? Full HD resolution?
Title: Re: Get Rid of Fireflies in Animation
Post by: BigAl3D on 2021-11-30, 00:44:24
It's only 15 passes. Took between 8 and 9 hours on one iMac Pro with 18 cores. 120 HD frames so around 4.5 minutes per frame. My small render farm was already rendering something else. There will be a woman green-screened standing between the rows.