PBR: Conflicting information on the web?
polycounter lvl 10
According to this guy:
http://forum.unity3d.com/threads/albedo-charts-for-pbr.276664/#post-1836486
Microsurface and metallness is engine-dependent, while Albedo and Specular color values are engine-independent - ie the albedo value for gold in one engine is the same as in any other engine.
Is this really correct? Because I´ve found conflicting information on the internet regarding this. For example, in the unreal docs (https://docs.unrealengine.com/latest/INT/Engine/Rendering/Materials/PhysicallyBased/index.html) the albedo value (base color) is 252 220 148 - or as floats: 1.000, 0.766, 0.336
But... Quixel does seem to think otherwise: http://www.marmoset.co/wp-content/uploads/materialref02.png - Here, gold has an albedo value of 0 0 0
Can someone straighten this out?
EDIT: Another thing that adds to the confusion is the use of the words "base color" when refering to albedo. Base color can also refer to the color on a specular map, as specified here:
https://seblagarde.wordpress.com/2012/04/30/dontnod-specular-and-glossiness-chart/
...but as you can see in the unreal docs, "base color" and "specular" is not the same thing.
http://forum.unity3d.com/threads/albedo-charts-for-pbr.276664/#post-1836486
Microsurface and metallness is engine-dependent, while Albedo and Specular color values are engine-independent - ie the albedo value for gold in one engine is the same as in any other engine.
Is this really correct? Because I´ve found conflicting information on the internet regarding this. For example, in the unreal docs (https://docs.unrealengine.com/latest/INT/Engine/Rendering/Materials/PhysicallyBased/index.html) the albedo value (base color) is 252 220 148 - or as floats: 1.000, 0.766, 0.336
But... Quixel does seem to think otherwise: http://www.marmoset.co/wp-content/uploads/materialref02.png - Here, gold has an albedo value of 0 0 0
Can someone straighten this out?
EDIT: Another thing that adds to the confusion is the use of the words "base color" when refering to albedo. Base color can also refer to the color on a specular map, as specified here:
https://seblagarde.wordpress.com/2012/04/30/dontnod-specular-and-glossiness-chart/
...but as you can see in the unreal docs, "base color" and "specular" is not the same thing.
Replies
However, in a specular workflow the color of your metals should be black and their 'base color' goes into the specular map. In a metalness workflow you put the color of the metal (in this case 252,220,148 ) into the albedo and you make sure that they are white in the metalness map.
I think your confusion comes from not understanding the difference in workflows here. You can look further into this on several of the topics on this forum.
Edit: In order to confuse you more, it's probably important to note that while rendering, metalness shaders will grab anything within the mask on the albedo, set the color to black, and tint the color of the relfection based on the original color.
Some of the best ref for PBR can be found here: https://docs.google.com/document/d/1Fb9_KgCo0noxROKN4iT8ntTbx913e-t4Wc2nMRWPzNk/edit
So I guess then that the example that I posted (from Quixel) is a chart for use with the specular workflow?? (Chrome and Gold have a black albedo there)