SP - PBR Workflow in Viewer?

GhosTDoG

[FONT=&quot]Hi,[/FONT]
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[FONT=&quot]Just watched the main [FONT=&quot]t[/FONT]utorials concerning Substance Painter and got some [FONT=&quot]q[/FONT]uestions regarding PBR and Shaders.[/FONT]
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[FONT=&quot]The PBR system is based on the roughness/metalness workflow, so I'm asking myself how Painter is useable for gloss/specular workflows?[/FONT]
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[FONT=&quot]1) There are only PBR Shaders for the roughness/metalness workflow in the viewer, why no shaders for gloss/specular?[/FONT]
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[FONT=&quot]2) Under [FONT=&quot]e[/FONT]xport settings you got templates for gloss/specular workflows like Cryengine, but at the moment I doubt a bit that a 100% clean conversion is possible?[/FONT]
[FONT=&quot]For instance metal gets its surface color in mixed-material textures from colored values in the specular texture. Unreal gets, afaik, the metal color values from the diffuse map (also roughness is inverted).[/FONT]
[FONT=&quot] In cryengine for instance, metal is almost black in the diffuse texture.[/FONT]
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[FONT=&quot]So, does the conversion really work properly?[/FONT]
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[FONT=&quot]Thx[/FONT]

oblomov

1) There are only PBR Shaders for the roughness/metalness workflow in the viewer, why no shaders for gloss/specular?

Lack of time to implement/maintain the feature mostly. Also the fact that conversion from metal/rough to spec/gloss is feasible. We will bring back the spec/gloss shader in a future update.

2) Under export settings you got templates for gloss/specular workflows like Cryengine, but at the moment I doubt a bit that a 100% clean conversion is possible?

100% accurate conversion from metal/rough to spec/gloss is possible.
The opposite conversion is not always possible however, but the materials you can do with spec/gloss and can't with metal/rough are most of the time not physically plausible (e.g. non metals with colored specular reflections)
In Unreal, the texture you get the colors from should not be called "Diffuse" but "Base Color" or something like that, because it does contain both the diffuse color of the non metal parts and the specular color for the metal parts. It really is not a diffuse texture.

GhosTDoG

@oblomov

Thx for the detailed explanation

100% accurate conversion from metal/rough to spec/gloss is possible.
The opposite conversion is not always possible however, but the materials you can do with spec/gloss and can't with metal/rough are most of the time not physically plausible (e.g. non metals with colored specular reflections)
In Unreal, the texture you get the colors from should not be called "Diffuse" but "Base Color" or something like that, because it does contain both the diffuse color of the non metal parts and the specular color for the metal parts. It really is not a diffuse texture.

O.K, if the conversion to spec/gloss PBR is no problem, you'll also got the advantage, that you can publish for different target engines.

So, as long as the viewer reflects, what I get in the target engine, it doesn't matter for me, if I paint in a roughness channel or a gloss channel etc.

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(e.g. non metals with colored specular reflections)

Yeb, but that's nonsens anyway. Most non-metals actually got no specular values/textures and tinted specs for non-metals is a big no-go.