Hi!
Comming from a specular/gloss workflow, I’m just a bit confused with the metallic/smoothness way of doing it. (Guess this is not just relating to unity, but it’s the package I currently use.) I kind of get what the smothness slider does; it makes the surface appear just more or less “smooth”. What I don’t really get is the notion of more or less “metallic”. More or less spec, I do get, but aren’t things always either metallic or not? Where would you use, let’s say, 50% metallic? Where would you put, lets say, a stone, or wood? Just feels wrong to use a slider called “Metallic” for objects not typically consisting of metall. Please enlighten me. 
