Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] I need help! => Topic started by: p_ktlr on 2024-02-02, 22:28:24

Title: Metal Material Import
Post by: p_ktlr on 2024-02-02, 22:28:24

Hi there,

I have an issue with metal textures in cinema 4D with corona. They tend to be way to dark and nothing like the preview on e.g. poliigon.
I attached screenshots on how I linked the different maps. If any of you can tell me what I'm doing wrong, I'd appreciate your help!

cheers
/Users/patrickuttler/Desktop/Bildschirm­foto 2024-02-02 um 22.13.49.jpg
/Users/patrickuttler/Desktop/Bildschirm­foto 2024-02-02 um 22.20.08.jpg
/Users/patrickuttler/Desktop/Bildschirm­foto 2024-02-02 um 22.20.18.jpg

Title: Re: Metal Material Import
Post by: burnin on 2024-02-03, 18:09:47

Hi, you got no images there.
Anyways, is your "Linear Workflow" set and on?

Title: Re: Metal Material Import
Post by: p_ktlr on 2024-02-03, 21:57:26

Hi I hope the screenshots did upload now. To be honest, I do not know what "Linear Workflow" in Cinema 4D is....

Title: Re: Metal Material Import
Post by: James Vella on 2024-02-04, 08:13:08

From what I see you have a few issues here.

- First you are using gamma 2.2 for your linear textures.
- You are also using Metal workflow for Specular textures
- You have a texture in your IOR slot, I dont see an IOR texture in that list.
- These will all compound if you are unsure of what you are doing for this texture set.

You can use the Poliigon C4D tool and do a bit of reading on their website regarding the Specular workflow/textures:
Poliigon Material Converter Addon for Cinema 4D (https://help.poliigon.com/en/articles/2540985-poliigon-material-converter-addon-for-cinema-4d)
Technical Asset Information & FAQ (https://help.poliigon.com/en/articles/8230518-technical-asset-information-faq)

Title: Re: Metal Material Import
Post by: p_ktlr on 2024-02-04, 19:28:40

Hi James,

thanks for your answer. Do I need to change that gamma value? I tried downloading the same texture once with metal workflow and once with specular. With the metal workflow I get a good result. With the specular one not. The material is almost completely black.

I was told by someone to put the Reflection map in the IOR slot. That why i did it.

Also thanks for the links, I red the articles.

Title: Re: Metal Material Import
Post by: James Vella on 2024-02-04, 19:55:01

Quote from: p_ktlr on 2024-02-04, 19:28:40

thanks for your answer. Do I need to change that gamma value?

Follow this guide  (https://help.poliigon.com/en/articles/1712652-texture-maps-explained)for which textures Poliigon require gamma 2.2 (srgb) and gamma 1.0 (linear)

Quote from: p_ktlr on 2024-02-04, 19:28:40

I tried downloading the same texture once with metal workflow and once with specular. With the metal workflow I get a good result. With the specular one not. The material is almost completely black.

Use the metal workflow in my opinion. Corona Physical Material works well with this.

Quote from: p_ktlr on 2024-02-04, 19:28:40

I was told by someone to put the Reflection map in the IOR slot. That why i did it.

Nope, don't do that. That's incredibly bad advice.

If you want to know more about IOR and reflectance (not reflection!) You can read more about it in an article (https://jamesvella.net/2020/04/20/2019-9-2-substance-designer-to-vraycorona/) I wrote some time ago (now outdated for Corona but the concept is still relevant for fresnel IOR). Reflectance (at f0) and reflection textures are quite different to each other and if you are using the metal workflow, don't bother with IOR, leave it at the default values (unless you have some understanding of how IOR works).

Title: Re: Metal Material Import
Post by: p_ktlr on 2024-02-12, 14:08:03

Hi James thanks for your answer! I will have a look into your article.

Cheers Patric