If a texture has white in it, then I need to darken the whole texture. Right?
But why should I darken the texture that has white in it, together with all the other colors in the texture, and not all other textures in the scene, that don't have such bright colors, at the same rate?
This is a mine field.
"But why should I darken the texture that has white in it, together with all the other colors in the texture"If a texture contains white as a value of 255,255,255 then it's just wrong and all of the other colours in that texture are likely to be the wrong values relative to the white. But simply put white whites at 255,255,255 is wrong. So it's easy for these 'guides' to highlight that. Same with black, although I personally think that black PBR standard of "30-50" is also wrong. But I'm no expert. Far from it in fact so who am I to say. So take the rest of what I say with a pinch of salt.
Check out Martins article here for more info on 'blacks' -
https://www.racoon-artworks.de/blog_PBRfromrulestomeasurements.php"and not all other textures in the scene, that don't have such bright colors"As far as the 'other textures' go that are full of mid-range values, who knows. That's for you to decide (or verify).
"At the same rate"Not all textures are made equal, I'm assuming you grab textures from various different sources and each creator will have their own workflows and processes to capture said textures, who knows if they're all done to the same "standards" or any standards at all. So you might have two textures from two different sources and they might both be wrong. But they might not both be wrong to the same degree relative to each other, if that makes sense.
In my opinion, following a 'strict' PBR workflow is only really possible if you're creating all of your own assets from scratch. Failing that, ideally you should be checking and correcting each and every texture to get all of your textures from all of your different sources as consistent as possible in terms of the 'correct' values.
Wanna know what I do ... make sure there are no white whites and no black blacks, then eyeball the rest. As already mentioned, if it looks right, it is right. When I'm creating a material, I tend to have real world references up on screen, of that material under the same or very similar lighting conditions as the lighting in my 3D scene. I then get the overall shader looking roughly correct in terms of reflection/roughness/bump etc (I often do this with no albedo texture, just a mid desaturated red colour), and then add the albedo to the mix and tweak using CoronaColorCorrect nodes (brightness, saturation, hue) until my scene and the reference look pretty close. Once they're pretty close then I'm happy.
I do use the Albedo render pass element as Tom suggested to check my scenes just before rendering, and if anything is red, then I consider it 'out of range', and so I tend to fire up IR and drop the diffuse level on that objects material until it's no longer red in the albedo render element and back 'in range'. I only do this for small things though where you wouldn't really notice if their textures are really the 'correct' values or not. And for some reason it always seems to be book covers and artwork that need fixing :)
Jumping back to strict PBR stuff - "In Range" and "Correct" are two very different things.
Hope it helps (assuming what I've written isn't absolute nonsense).
