Need clarification about PBR Rougness+Metalness workflow. Please help!
polycounter lvl 7
Hello everyone!
I decided to duplicate my Tech Talk post here in Marmoset section also just in case. If it's against forum rules feel free to delete it in Technical Talk section.
So, sorry for may be lame questions but I'm absolutely new to this PBR concept and quite scared of doing things the way I shouldn't.
So this is my scene of wooden planks in Marmoset. Please have a look at the maps I made and the shader setup.. Here's what I'm striving to learn:
1. Is my Albedo map is correct in sense of Material Values Chart for wood material? How do I check if my ALbedo is correct for certain material types? How exactly do I have to use those three color swatches given in that chart? I do understand that I have to color pick lets say roughness swatch in that chart and later be aware not to exceed that maximum drawing my grayscale map in photoshop but how to use Albedo color swatch and what "Reflectivity" color swatch is for?
2. My main material is wood, so what should I do with the default Specular slot in Marmoset's shader? Currently I couldn't think of anything better than just changing "Specular" to "Metallness" slot and just set it to 0..
3. Do you think my Rougness map is ok and the way it should look? I'm concerned because obviously my wood planks look very unrealistically smooth even if I make prominent Normal details - they just start to look like plastic toys with carved wood texture. My roughness map won't help, what am I doing wrong?
4. There's a "Reflection" slot in Marmoset with Horizon Occlusion slider in it. What it really does?
Hope I didn't bore you with my silly questions. Thanks in advance!
I decided to duplicate my Tech Talk post here in Marmoset section also just in case. If it's against forum rules feel free to delete it in Technical Talk section.
So, sorry for may be lame questions but I'm absolutely new to this PBR concept and quite scared of doing things the way I shouldn't.
So this is my scene of wooden planks in Marmoset. Please have a look at the maps I made and the shader setup.. Here's what I'm striving to learn:
1. Is my Albedo map is correct in sense of Material Values Chart for wood material? How do I check if my ALbedo is correct for certain material types? How exactly do I have to use those three color swatches given in that chart? I do understand that I have to color pick lets say roughness swatch in that chart and later be aware not to exceed that maximum drawing my grayscale map in photoshop but how to use Albedo color swatch and what "Reflectivity" color swatch is for?
2. My main material is wood, so what should I do with the default Specular slot in Marmoset's shader? Currently I couldn't think of anything better than just changing "Specular" to "Metallness" slot and just set it to 0..
3. Do you think my Rougness map is ok and the way it should look? I'm concerned because obviously my wood planks look very unrealistically smooth even if I make prominent Normal details - they just start to look like plastic toys with carved wood texture. My roughness map won't help, what am I doing wrong?
4. There's a "Reflection" slot in Marmoset with Horizon Occlusion slider in it. What it really does?
Hope I didn't bore you with my silly questions. Thanks in advance!
Replies
The first thing to realize here is that the chart is simple example materials, not rules that all wood is X color. There is no correct albedo color for wood, because wood naturally will vary in color to a huge degree. What you have looks fine.
Even roughness will vary to a huge degree, think very old, rough, dry wood, and then fresh polished wood, the gloss would vary significantly there too. Again there is no correct value, just an appropriate value for the specific material you're trying to represent, finding reference here is key.
Specular for wood should be somewhere around 4%, so swapping to metalness and setting it to 0 is fine (that also sets it to 4%). If you want to use your asset in UE4 later the metalness workflow is what you want to use as well.
Be sure to read this PBR conversion guide, it covers the differences between the metalness and specular workflows in great detail: http://www.marmoset.co/toolbag/learn/pbr-conversion
The gloss map looks ok, it looks like you just took the albedo and desatured it though. If you think about it, what the gloss map defines is how smooth or rough the surface is. When you make a gloss map by desaturating an albedo map, what you're telling the shader is the bright parts of the albedo (simply color variation in this case) are more smooth, when in reality there we be little correlation between color variation and surface structure. Check out the quixel scan material examples (in the material preset dropdown), there should be a wood one, take note of how the gloss map varies from the albedo map.
If your material starts to look too plasticy when you use a more pronounced normal map, changes are your gloss map is making the material too glossy. Again unfinished would would be pretty rough.
Horizon occlusion reduces illogical specular reflections from normal map details which would face away from the light source. Its a technical thing that you don't really need to worry about.
No worries, I hope this was helpful.
Can you clear up this for me please? Is it something that is in their dDo photoshop plugin?
Oh and one other thing, it was touched on in your other thread but its worth mentioning again as you've refered to a roughness map.
By default, Toolbag 2 uses a gloss map, which means black = rough surfaces and white = smooth surfaces. With a roughness map, typically the value scale is reversed, so black = most smooth and white = most rough. There is an invert box in the gloss slot so you can load a roughness map as this is the only difference between the two map types. Again if you want to use your asset in UE4, you should use the roughness standard instead of gloss.
Marmoset is rocking!