[WIP] Hair Material with anisotropic reflections

[MizuGames]

@dzodzu;233342

Yay, thread bookmarked

Ty!

@cmartel;233472

Have you looked into Marschner’s hair model? Kajiya-kay is rather dated (though it has the advantage of being highly straightforward) and doesn’t hold up very well in modern scenes. Without the second highlight coming from backscattering, situations where characters are backlit feel like something’s missing. Plus, it’s not physically based, which is rather important to maintain in UE4.

Marschner’s model is very technical but it’s the building block for Disney’s model, which retains the physically based constraints but instead adapts the inputs to more intuitive ones.

Yep, the main base are from Scheuermann’s GDC 2004 presentation, mix of Kajiya-kay and Marschner’s model, “simple” but I think that it works