I’m working on a beach that has both dry and wet sand. But I have a few questions for a while like a splinter into my mind.
A) For the dry sand, I’m keeping the median at 166 according to the charts, a roughness value of 0.9 (or 1), leaving specular and metallic slots blank. However, to achieve true PBR I assume I have to give sand a specular value. But since it’s a 0 to 1 and not a 0 to 255 range I’m a little confused. (I used to give sand 53,53,53 in cryengine, but yet it wasn’t accurate, eye was the judge).
B) What other parameters I’d have to take care of when trying to achieve an all PBR accurate environment. I mean, is the sun/sky/auto exposure/etc. intensities involved with this? because sun doesn’t shed light on earth with random intensities. It’s the outer parameters affecting the intensity like the atmosphere, clouds etc. So the sun intensity itself has to have it’s own physically correct value range? I used to follow some guide in CRYENGINE for setting up a PBR friendly lighting but in UE4 I’m not doing anything particular.
C) When creating a wet version of the same sand, other than reducing the roughness the specular has to be modified too since water has a different specular itself (but still I’m not sure where the correct values stand in a 0 to 1 range). What I could do is to pick the values from charts, create a specular map and feed it to the specular slot but I just don’t want to do that when I can do the same thing using a constant. So I need to know how to quickly find out where for example 61,61,61 stands in a 0 to 1 range.
D) Because wet sand is darker than dry sand, we’d have to darken the texture in material, or is there a better way to achieve that?