Marmoset TB2 Viewer "Layer view" help.

[johnny9ball]

https://www.artstation.com/artwork/copper-ingot

Hi the viewer channels are mixed up. I am using PBR. Modeled in Maya surfaced in Substance Painter. With Normal, Albedo, Roughness, Metal, maps. I put all the maps in the correct slots with the correct settings and it looks great but the viewer "Layer View" is incorrect the Reflectivity and Albedo maps are reversed/named incorrectly and the Reflectivity should be called Metalness. The Topology contains normal data.

Am I doing something wrong? I included the viewer export at artstation for you to look at. Thanks for helping.

[johnny9ball]

Looking at others models I see the same problems. The Reflectivity is the albedo map exactly. The Albedo is the inverse Metal Map.

[Fabian F.]

Hey John,

for me it appears quite correct and logical. I didn't make tests and didn't take too long to take a look at Marmoset Viewer, unfortunately, so I am not 100% sure with that.

I assume that Marmoset Viewer is utilising the PBR Spec/Gloss Workflow, because it uses the maps 'reflectivity' and 'gloss'.
That means:
For metals the Albedo is black (like your copper), because metals do not refract light, they just reflect it.
The reflectivity/specular is coloured for metals (like your copper) because metals absorb light waves and 'colour' the reflected light that way.

As I said above: I didn't make tests, unfortunately, so I am not sure if there is a way or not to utilise the Metal/Rough workflow.
Your Material appears to be shown correct, anyway.

If you want to learn more about PBR and how light interacts with surfaces I recommend reading the PBR Guides by Wes McDermott. It can be found here: https://www.allegorithmic.com/pbr-guide


Best Regards

[johnny9ball]

Ahh I never thought of it that way I was just thinking of the input maps showing up not the PBR Effect/Theory on the surface giving the final layers map output.

It does make logical sense if you take into consideration the way PBR Theory interacts with the surfaces.

[johnny9ball]

Also Marmoset Toolbag 2 is Amazing. The Viewer is far beyond Sketch Fab and more artist friendly since they give you the files and you can host them anywhere.

[johnny9ball]

I need to do some more tests but I cant figure out why what I think should happen isn't happening with certain Layers in the Marmoset viewer. And objects with the same type map surfaces are giving different results. I am probably doing something wrong going to do some testing.

This is confusing. I will provide the layers view with the associated maps. I am using the same settings to apply the maps in Marmoset Viewer and all the objects with maps all look great in Marmoset. Very very close to substance Painter. I applied them as you instructed in the other thread.

So I load up my cinder block. Which is completely non metallic black metal map. And this is the results the albedo layer is completely black. Reflection layer looks like the albedo map. A lot like the Ingot. Image 1

https://www.artstation.com/artwork/cinder-block

Then I load up my Barrel which is mostly non metallic painted surfaces and dirt with spots of metallic rust and it gives completely different Viewer Layer results. The Reflectivity layer looks a lot more like the Roughness channel and the Albedo layer looks exactly like the albedo map. Image 2

https://www.artstation.com/artwork/barrel-a87c13bf-6d8e-43df-acab-2615416cd8c3

Then I load up a barrel without any paint but a lot of rust and dirt. So a mixed metallic and non metallic map. The Reflectivity and Albedo looks the same mostly Reflectivity is a little lighter and the gloss looks like the roughness. Image 3

https://www.artstation.com/artwork/barrel-a87c13bf-6d8e-43df-acab-2615416cd8c3

[johnny9ball]

Ok First mistake the Metalness map for the cinder block in Marmoset was not set I missed that somehow duh. Ok fixed. Now the Layers give a predictable result. Now the Cinder block looks like the first Green Barrel. The Viewer Layer channels all look correct.

I am also posting and going through my solutions so others can learn from my mistakes and maybe learn a little how marmoset works.

[johnny9ball]

Now I understand the rest from this article.

http://www.marmoset.co/toolbag/learn/pbr-practice

Correct me if I'm wrong.

Basically the Metalness map (white) uses the Albedo for the diffuse value That's why white on the metalness map gives the Reflectivity the Albedo look on the layers channel in Marmoset. And why the Albedo is black also is because the Albedo is set to 0 in the shader because the Metalness map.

When using a metalness map, insulative surfaces - pixels set to 0.0 (black) in the metalness map – are assigned a fixed reflectance value (linear: 0.04 sRGB: 0.22) and use the albedo map for the diffuse value. For metallic surfaces – pixels set to 1.0 (white) in the metalness map – the specular color and intensity is taken from the albedo map, and the diffuse value is set to 0 (black) in the shader. Gray values in the metalness map will be treated as partially metallic and will pull the reflectivity from the albedo and darken the diffuse proportionally to that value (partially metallic materials are uncommon).

So we learned a lot today I hope my posting makes it easier for others to understand also.

[Fabian F.]

Hey John,

you need to distinguish between the Metal-Rough Workflow and the Spec/Gloss Workflow. Those are not the same and those shouldn't be mixed up.

In the Metal/Rough Workflow you use these three maps: Base Colour, Metallic, Roughness
In the Spec/Gloss Workflow you use these other three maps: Diffuse/Albedo, Specular, Glossiness

In the Base Colour/Albedo dielectric materials are authored exactly the same.
The Roughness is the inverted glossiness map and vice versa.
For dielectric materials the metallic will be black (no metal) and the shader uses a 4% specularity as default. The Specularity map is authored the same: 4% specularity defined by a greyscale value.

The interesting part comes when you have conductors/metals.

Roughness & Glossiness: Authored the same way as ever.
Base Colour & Metallic: If the metallic map is white the specularity value is taken from the Base Colour (because of the lack of the Specularity map in the Metal/Rough workflow)
Diffuse/Specular: Because you have a Specular map now you can colour the metal and give it a way higher spec greyscale value.
Since it is a metal material now you need to make the diffuse black, because metals have no colour themselves.

Toolbag uses the Spec/Gloss workflow, that's why it converts your Metal/Rough maps. That's all.

Hope that helps you a bit.


Best Regards

[johnny9ball]

Thanks for the Pro tips. There is a lot to wrap my head around with PBR.

[Wes McDermott]

Thanks for the Pro tips. There is a lot to wrap my head around with PBR.

Hi,

We have a PBR guide which helps to explain the theory and practical guidelines for creating PBR maps. Please let me know if you have any questions.

https://www.allegorithmic.com/pbr-guide

Cheers,

Wes

[johnny9ball]

Ya I understand the channels now a lot better. Now if they could just put Marmoset on sale again. I'm on day 10ish of my free trail.