PBR Noob question
polycounter lvl 11
Hi,
Apologies for asking what is no doubt already seen as a very basic question but tonight is my first time trying to use PBR texturing (in UE4) after years of the usual methods and I just wanted some confirmation that I'm thinking along the right lines for authoring textures
So, is the below correct or am I barking up the wrong tree? :polytwitch:
Diffuse - Should be flat colour information, as the surface would be seen under a totally neutral light, no AO included, etc.
Specular - Intensity/brightness of specular highlight, flat colour value per surface type
Roughness - Controls the gloss / tightness of specular highlights. Black being a tight spot highlight spreading through to white which would be wide to the point of no highlight.
I just can't quite think how I would go about making skin textures based on that. How are you supposed to know what sort of values to use for things to be physically accurate?
</moron moment>
Apologies for asking what is no doubt already seen as a very basic question but tonight is my first time trying to use PBR texturing (in UE4) after years of the usual methods and I just wanted some confirmation that I'm thinking along the right lines for authoring textures
So, is the below correct or am I barking up the wrong tree? :polytwitch:
Diffuse - Should be flat colour information, as the surface would be seen under a totally neutral light, no AO included, etc.
Specular - Intensity/brightness of specular highlight, flat colour value per surface type
Roughness - Controls the gloss / tightness of specular highlights. Black being a tight spot highlight spreading through to white which would be wide to the point of no highlight.
I just can't quite think how I would go about making skin textures based on that. How are you supposed to know what sort of values to use for things to be physically accurate?
</moron moment>
Replies
http://www.marmoset.co/toolbag/learn/pbr-practice
In this case...
diffuse = albedo
roughness = microsurface
specular = reflectivity
I've read through that before and it's a mountain of info to take in. I'm just having a senior moment where I need someone to say yes or no to what I've written above, i.e. have I understood it?
Oh... so why have I got inputs on the material for both 'Metallic' and 'Specular'?
And if I'm using subsurface then do I still require the other maps?
On top of what you said, specular tends to be very polar, where most materials are barely reflective or highly reflective (almost white and almost black on the actual texture), that's why the metalness workflow exists.
Do not use specular in UE4, it's not PBR.
The metalic input is usually called substance in other engines. Might be good to remember if you watch some tutorial.