Trying to learn pbr
polycounter lvl 8
Hello
I'm trying to learn how to make PBR materials. I will post my progress here. I started from something simple. This is 1st time when i use specular map, so i'm not sure it is correct and i hope you will help me.
Here is the barrel, and maps. Screens are from marmoset toolbag. Please let me know what do you think about it
EDIT" I also have question to people who use UE4. When i imported my barrel to engine, specular map doesn't work. Rest of map was fine. Someone maybe know where is the problem? Or UE4 doesn't work like toolbag?
I'm trying to learn how to make PBR materials. I will post my progress here. I started from something simple. This is 1st time when i use specular map, so i'm not sure it is correct and i hope you will help me.
Here is the barrel, and maps. Screens are from marmoset toolbag. Please let me know what do you think about it
EDIT" I also have question to people who use UE4. When i imported my barrel to engine, specular map doesn't work. Rest of map was fine. Someone maybe know where is the problem? Or UE4 doesn't work like toolbag?
Replies
I think, though, the red plugs and the rust on your spec map should actually be a mid-light grey.
Not sure about the values associated with metallic paint, but your blue paint should probably also have a less saturated/grey spec if it's just a regular coat of paint. I'm new to this stuff too, though, so I'd say research your spec map a little more.
Keep it up!
UE4 takes that info from the albedo for all the areas that are masked as white in the metalness map and automatically sets the base color to black. So no need to use a specular there unless you wanna further control the reflections, right?
this video explains the differences pretty well: https://www.youtube.com/watch?v=LP7HgIMv4Qo
I would assume this aswell. Since the paint isnt metallic, its rather diffuse. Also it gives a good reason to break up the roughness a bit moore than it is right now.
http://www.marmoset.co/toolbag/learn/pbr-theory
http://www.marmoset.co/toolbag/learn/pbr-practice
Only difference i know of is that a diffuse can have AO in it but an Albedo cannot. I'm still new at PBR and i dont really know the differences to be honest
You can add some details from specular to albedo. (things like rust, dirt, mud... change colour so they should be present in albedo)
Desaturate your spec map. You want to use colours in specular rarely (on metals like gold, silver...)
Roughness map is great, as is normal.
You could also add cavity and AO (as individual maps), for even more detail.
I agree with those above, desaturate the spec. As you see in the reference image, the spec highlights are white.
No, specular is there for reflecions, you add colour only if reflections are colored. And no, roughness isn't specular. Specular is amount of reflection (white - pure reflecion, black - only fresnel reflecion), while roughness is bluriness of reflection (white - blurry, black - sharp, mirrorlike).
ghaztehschmexeh already posted great link explaining it.
If you still don't get it, then just play with it in marmoset and see how things change.
http://artisaverb.info/PBT.html
- If you are going to UE4: Albedo, Normal, Metallic, Roughness, AO
- If you are going to spec/gloss: Albedo, Normal, Spec, Gloss, AO
Elements of an Oil Drum Barrel:
- Paint = None metal
- Rust = None metal (Debated a lot due to transitions)
- Steel = Metal
Detailed info and charts here:
https://docs.google.com/document/d/1Fb9_KgCo0noxROKN4iT8ntTbx913e-t4Wc2nMRWPzNk/edi
The specular would mostly be 45-65 grey (or black if metallic workflow) as its paint, not the opposite of blue.
+9000
Very, very, very no. Inverse color thing only applies to old engines with broken gamma space issues, not TB2, nor any other engine claiming to be have a pbr workflow.
Spec map should not have any color and should be much darker. Reflectivity for non-metals is usually around 4%, a painted metal barrel shouldn't be thought of as metal, you're representing the paint layer on top.
UE4 uses the metalness workflow, not spec map workflow. The spec map in UE4 is not a traditional spec map at all, but more of a specular cavity map.
More on pbr in TB2 including the differences between metalness vs spec map workflows here: http://www.marmoset.co/toolbag/learn/pbr-theory
and here: http://www.marmoset.co/toolbag/learn/pbr-practice
If you want to preview your work in TB2 before sending it to UE4, use the Unreal 4 preset material (in the preset material dropdown) to get the most accurate material setup.
Official docs from epic here: https://docs.unrealengine.com/latest/INT/Engine/Rendering/Materials/PhysicallyBased/index.html
^ This goes over the "specular" input in UE4, which again, isn't really a specular input as you would think.