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Unity 5 PBS physically based lighting question, which direction to go?

Discussion in 'General Discussion' started by adamz, Jul 31, 2014.

  1. adamz

    adamz

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    Does anyone know if Unity is going the Roughness/Metallic or Specular/Glossiness route? I ask because I'm creating Substances and I'd like to set them up correct so they're ready to go when 5 ships.

    Thanks.
     
  2. Andy-Touch

    Andy-Touch

    A Moon Shaped Bool Unity Legend

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  3. Andy-Touch

    Andy-Touch

    A Moon Shaped Bool Unity Legend

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    It does yarn pretty well too. :)
     

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  4. adamz

    adamz

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    It looks great, but Im looking for more of which inputs/outputs they're going to use; either Roughness/Metallic or Specular/Glossiness.
     
  5. Whippets

    Whippets

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    Or both as a settable option? From what I've read on PBR it should use Roughness/Metalic to make a clean break from the old Specular/Glossiness
     
  6. jmatthews

    jmatthews

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    He replied that they're using spec/gloss. Once you get used to the workflow it is more logically consistent that way.(IMHO)
     
  7. adamz

    adamz

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    Is Specular/Gloss better than Roughness/Metallic? Im curious since Unreal Engine 4 uses Roughness/Metallic.
     
  8. Andy-Touch

    Andy-Touch

    A Moon Shaped Bool Unity Legend

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    I haven't used Unreal Engine 4 or a Roughness/Metallic PBR-supported shader, but I would personally prefer a Specular/Glossy shader that allowed for users to have alot more variation in materials, rather than just making metal sci-fi corridors. :)

    Of course, you can make metal sci-fi corridors with the Unity 5 Universal Shader, ill put together a demo and post it here at some point this weekend (next opportunity I have!)
     
  9. makeshiftwings

    makeshiftwings

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    Roughness is just the inverse of Gloss; there's really no difference. You can get one from the other by just inverting the colors in Photoshop or Substance Designer.

    Metalness vs Specular is different. Metalness uses less memory, while Specular lets you get slightly more realistic highlights on rare complex materials. So it's a tradeoff. Here's a good explanation:

    http://www.marmoset.co/toolbag/learn/pbr-practice#refl
     
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  10. KRGraphics

    KRGraphics

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    Personally, I have grown quite fond of the roughness/metallic workflow... it gets me closer to emulating real world materials. I am a user of Alloy.
     
  11. zDemonhunter99

    zDemonhunter99

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    Did you try using Shader Forge instead of waiting for Unity 5?
     
  12. Aras

    Aras

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    I had quite some info in my GDC talk: http://aras-p.info/texts/files/201403-GDC_UnityPhysicallyBasedShading.pdf (slides) and http://aras-p.info/texts/files/201403-GDC_UnityPhysicallyBasedShading_notes.pdf (slides with notes).

    Basically, current iteration of the shader goes a "separate diffuse & specular colors" route. So metals would have black diffuse, and fairly high specular color. Non-metals would have grayscale and fairly dark specular color.

    Roughness is independent of colors and affects both. We call it "smoothness" I think - i.e. it's the opposite of roughness (black = rough, white = smooth).
     
  13. Devil_Inside

    Devil_Inside

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    Nice presentation! Thanks for the slides!
     
  14. shkar-noori

    shkar-noori

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    Thank you for the presentation, it was really helpful.
     
  15. adamz

    adamz

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    Thank you.
     
  16. Whippets

    Whippets

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    That poor doll looks like she's suffering dreadful arthritis in her fingers.
     
  17. Zomby138

    Zomby138

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    How easy will it be for us to write our own shaders that emulate this "one shader to rule them all"? For instance if I wanted to make a shader with an animated albedo channel that still renders with PBS.
     
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  18. shkar-noori

    shkar-noori

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    @Aras do we have any chance of a native Decal solution in U5?
     
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  19. adamz

    adamz

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    Aras, do you know if this uber shader will also include subsurface scattering for skin? What about distance based tessellation with phong?
     
  20. melkior

    melkior

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    Wow .. I'm glad I read the forums I've been designing all my substances with the roughness/metallic approach as I just assumed that would be the approach... guess I'll go redesign those substances now :) At least substance is fast & easy to do such things!
     
  21. Whippets

    Whippets

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    Yep, LUX has very nice skin, hair, and eye shaders - I hope the uber shader will be equally as good :)
     
  22. steego

    steego

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    You can also just use a conversion node like this http://forum.allegorithmic.com/index.php?topic=1368.15
     
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