Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] I need help! => Topic started by: MrGrizzler on 2022-10-26, 22:52:41

Title: Splotches on objects
Post by: MrGrizzler on 2022-10-26, 22:52:41

Hi there, relatively new to the Corona renderer. My render has large random dark splotches/burn marks (see attached screenshot) on each object and I can't figure out what's causing them. Any thoughts?

Thanks,
Chris

Scene file can be downloaded here:
https://www.dropbox.com/s/rhd3yfonxeavvjp/BC_001.zip?dl=0

Title: Re: Splotches on objects
Post by: BigAl3D on 2022-10-27, 03:36:32

Impossible to tell from just that image. I'm sure you'll have to post the scene file.

Title: Re: Splotches on objects
Post by: MrGrizzler on 2022-10-27, 04:23:14

Thanks for the heads up. Here's the scene file:

https://www.dropbox.com/s/rhd3yfonxeavvjp/BC_001.zip?dl=0

Title: Re: Splotches on objects
Post by: FS-Marc on 2022-10-27, 13:02:48

This is most likely caused by your Noise Shader in the Glossiness slot.

Try to soften that ohne until you dont get so obvios blobs (I would rather look for some surface imperfaction shader online to use and  put that in a "Color mix" - that  for time saving)

Keep learning and create great things,

Marc

Title: Re: Splotches on objects
Post by: Beanzvision on 2022-10-27, 13:16:25

I have rendered your image and do not see any splotches as mentioned.

(https://forum.corona-renderer.com/index.php?action=dlattach;topic=38241.0;attach=173520;image)

Title: Re: Splotches on objects
Post by: FS-Marc on 2022-10-27, 14:40:37

@Beanzvision

Very much depends on how you look at it - if you rotate the camera or move the light they become very clearly visible (you can also see them on top and on the right side of you render)

Title: Re: Splotches on objects
Post by: Beanzvision on 2022-10-27, 15:05:41

Have you checked the bump or reflection maps?

Title: Re: Splotches on objects
Post by: BigAl3D on 2022-10-27, 15:27:38

I agree with FS-Marc. It's definitely the noise in the Glossiness channel. Makes sense you would see it more at an angle with the Fresnel effect in play. Here is an example of yours on the left, and the noise shader's scale set to .05%. This is only 15 passes with no denoiser.

On the creative side, I would look at your shadows. To my eye, they seem very dark for such a bright room in my opinion. If that's the look you want, then you're done, just to my eye they seem too dark.