Roughness and Specular is possible?

SuSo

Hello!

I was wondering why some people create the face without following the standard PBR (Roughness/Metalness).

It's possible? I mean.. of course you can do it in Marmoset but in a studio it would be possible? And for example, if you have a head where it has some hard surface bake it and you want to use Roughness/specular in the skin but metalness for that piece of metal, how can you make it?

Thanks

Fabi_G

Hi! If the question it is whether it's possible to use mask defining the specular amount along with other PBR maps, sure it is. Iirc, when you leave the specular input empty in Unreals material editor, it will default to a value 0.5.

In a project environment, there's likely some rules or pre-built base materials to use. If a existing base material was lacking functionality, I'd bring this up to the art lead or tech art person. It might be on purpose because the benefit is too low.

SuSo

Fabi_G said:

Hi! If the question it is whether it's possible to use mask defining the specular amount along with other PBR maps, sure it is. Iirc, when you leave the specular input empty in Unreals material editor, it will default to a value 0.5.

In a project environment, there's likely some rules or pre-built base materials to use. If a existing base material was lacking functionality, I'd bring this up to the art lead or tech art person. It might be on purpose because the benefit is too low.

Hey Fabi, thanks for answering.
I see.. in my case maybe you can help me is because i have a sci-fi head in Marmoset that i use roughness and specular (instead of metalness, you know that you can use just one option there.. )  so.. how can i use both in this case? Should i make it the texture face just with metalness? Sorry if it is a stupid question but if the first time with this problem.

Thanks

Fabi_G

Oh, looks like I misread your original post.

What do you mean by non standard PBR? Using the Specular Reflectance workflow? Personally, I'm so used to working following the Metalness workflow, I'd have to look up Specular Reflectance. Maybe you find some information relevant to you in the wiki: Rendering

Maybe you could show some example what you mean?

Edit: I don't know if this is of relevance to the question, but in Toolbag setting Reflectivity to Advanced Metalness will allow to set a Specular Map and give Specular controls. Best read up here and experiment.

SuSo

Fabi_G said:

Oh, looks like I misread your original post.

What do you mean by non standard PBR? Using the Specular Reflectance workflow? Personally, I'm so used to working following the Metalness workflow, I'd have to look up Specular Reflectance. Maybe you find some information relevant to you in the wiki: Rendering

Maybe you could show some example what you mean?

Edit: I don't know if this is of relevance to the question, but in Toolbag setting Reflectivity to Advanced Metalness will allow to set a Specular Map and give Specular controls. Best read up here and experiment.

I tried the Advanced Metalness but the result is not looking like i want.
Look at this image and my settings, the line that he has in the face is metal and that's why I'm having this problem.



And using Advanced Metalness, it creates a light in the face

poopipe

You can represent metal using specular/gloss model easily

Put black in your diffuse texture and a bright value in the specular reflectance texture.  Something greater than around 150 in value will be a valid metal - strictly speaking it shouldn't be a perfect grey and should not be fully saturated but that doesn't matter. 
There are plenty of reference sheets with values that represent different metals

SuSo

Hey Poopipe
Okay i will try that and I hope to get the desired result.
Thanks

Fabi_G

Hm, interesting that the results are different, I wouldn't know why. Curious to see how your result using the specular reflectance workflow will turn out.

SuSo

Hey guys, i have been testing with specular/Gloss for the metal but i don't get the result that i want. I think i missing something.
Poopipe, when you told me about add a value around 150 where i supposed to be added that? 
I substance i can add just max 1.



I was wondering when a person creates something like this, Which method they use in Marmoset to get the correct result..?

poopipe

You're using metal/rough workflow in painter and trying to make it spec/gloss in marmoset

You need a  colour texture for specular reflectance and you need to change your painter file to support it - it not particularly difficult but first you'll need to understand what the difference between the two workflows is.
That's quite well documented so shouldn't be too hard to google

SuSo

I was reading a couple of things to get better idea about these two workflows.
So.. the point is, when you told me poopipe about colour texture for specular reflectance you were meaning to use a value color between 150 - 255 to be considered Metallic with Specular, right? When you told me that i was lost because for me it was Spec lvl that it's totally different and that's why i was wrong.

Just to be clear.. to get a good skin render i saw people using roughness and specular in Marmoset (using Spec lvl in subtance, not Specular that it's color sRGB) but in my case like you told me i have to use gloss and Specular sRGB (not Specular lvl), right? That's the correct workflow for this.

Eric Chadwick

Good skin requires subsurface scattering. https://marmoset.co/posts/creating-realistic-skin-toolbag-saurabh-jethani/

I think you still don’t have a good understanding of the two main PBR workflows: metal-rough, and spec-gloss. I would suggest reading up on how these work. https://marmoset.co/posts/pbr-texture-conversion/

We have a list of great PBR resources here: 
http://wiki.polycount.com/wiki/PBR

poopipe

there's literally no difference between the output of the two models if you include a specular level with metal/rough - the only difference is which texture the information lives in

for something to look like a metal you require a specular reflectance value of >150 sRGB as  input.   
that is defined in:
the basecolor texture for metal/rough(with the same area masked white in metallic)
the specular reflectance map for a spec gloss workflow (with the same area masked black in the albedo because metals don't have a diffuse contribution)

SuSo

I was reading all the articles and with the explication of poopie beside the articles, now i can understand the difference between them.

After read them i started redoing the metal again and now i have a good result like a want from the beginning.

Thanks all of you for use your time to help me, i really appreacite.

Cheers!