Formulas to Blueprint Scripting (Material-based)


I’ve been working on Unreal for a bit of time, yesterday I was reading Naughty Dog Tech Art PDF (that can be found here).

Then in page 46, that moss material got my attention; microfiber BRDF with sheen, Light Wrap, Fuzzy Shading and Parallax Shadows.
After searching the web, I failed to finding anything about Sheen in UE4 but I Found that Unreal have a function called “Fuzzy Shading Grass”.

Then Searching about Lightwrap that is:

Steve McAuley’s Extension to Energy-Conserving Wrap Diffuse (that can be found here) got my attention, but I got no experience in C++ to use the formula in UE4.

Someone could help me port that formula and the Microfiber BRDF model to Unreal so I can achieve the same effect or/and Would help if someone could help me understand the BRDF Microfiber formula (also can be found here at page 6) so I can port that to Blueprint Script?

I got stuck on how to get the angle from lights that affect the material, “light source” node only works with Deferred Decals, and “calclightsourceangle” function gives me a vector 3 value.