Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] I need help! => Topic started by: Schlee on 2022-06-11, 11:56:00

Title: How to avoid white border in Corona Renderer?
Post by: Schlee on 2022-06-11, 11:56:00

Hi all

I do get at Corona Renderer when using alpha channel (PNG) a white border after rendering.

I did watch some videos which mentioned in the render setting to select "direct visibility override".... but it doesn't help.

Any ideas?

Many thanks

Mike

Title: Re: How to avoid white border in Corona Renderer?
Post by: aler on 2022-06-11, 17:45:36

Quote from: Schlee on 2022-06-11, 11:56:00

Any ideas?

If this static, then Photoshop has this technique:
Ctrl+click by layer > Invert selection - Ctrl+Shift+I > press 2-3 times Del.

Title: Re: How to avoid white border in Corona Renderer?
Post by: burnin on 2022-06-12, 01:23:38

Straight Alpha... ?

Title: Re: How to avoid white border in Corona Renderer?
Post by: Schlee on 2022-06-13, 01:50:33

Hi and Thanks

@aler, this is a solution, but it looks after that it looks very pixelated.

@burnin, I have selected "Straight Alpha" in the render setting now, but I still see the white border. Do I have to consider something else?

Is there not a out of the box solution for this problem in Corona renderer?

many thanks

Mike

Title: Re: How to avoid white border in Corona Renderer?
Post by: ficdogg on 2022-06-13, 10:08:00

It's not a corona thing, its a C4D thing, saving out transparent PNGs out of the picture viewer is a very hit and miss thing. Just add the alpha as a render layer and then make it transparent in post.

Title: Re: How to avoid white border in Corona Renderer?
Post by: burnin on 2022-06-13, 13:20:12

Upscale/downscale, super-sample, feather...  Such is nature of alphas, filters, samplers, tone mappings, passes and apps one uses to compose perfection in detail.
Have you looked into cryptomatte (https://support.chaos.com/hc/en-us/articles/4954345529489-How-to-use-the-Corona-Cryptomatte-C4D) pipeline to ease the pain?

Title: Re: How to avoid white border in Corona Renderer?
Post by: Schlee on 2022-06-13, 13:45:37

Thanks!

@ficdogg, Is there a tutorial how to do so?

Many thanks

Mike

Title: Re: How to avoid white border in Corona Renderer?
Post by: Beanzvision on 2022-06-14, 11:43:59

Perhaps, this might help?
https://support.chaos.com/hc/en-us/articles/4528578885649-Objects-with-opacity-maps-are-becoming-gray-when-they-are-far-away-from-camera-

Title: Re: How to avoid white border in Corona Renderer?
Post by: piotrus3333 on 2022-06-14, 21:54:44

https://youtu.be/RR_PEZf4T4I (https://youtu.be/RR_PEZf4T4I)

Title: Re: How to avoid white border in Corona Renderer?
Post by: brr on 2023-03-29, 20:23:36

Quote from: piotrus3333 on 2022-06-14, 21:54:44

https://youtu.be/RR_PEZf4T4I (https://youtu.be/RR_PEZf4T4I)

thanks ! you saved me :)