Wanted to give a brief overview of this shader. You can apply this tutorial to nHair as well as xGen fur alike. I said 'refract' instead of 'reflect' a couple of times toward the end there, hope that doesn't bother anyone too much.
Pixar's website reference used in the video:
https://renderman.pixar.com/resources/current/RenderMan/PxrMarschnerHair.html
Wikipedia list of refractive indices:
https://en.wikipedia.org/wiki/List_of_refractive_indices
Check out more of my work here:
http://michaelrew.tumblr.com/
instagram.com/smallrobotstudio/
