Renderman’s Implementation of the Marschner Hair Shader
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Latest comments

Well, small/medium intuos pro is way cheaper that iPad Pro + pencil... just saying... And it works better with ZBrush...

by some guy
12 hours ago

It might ultimately be proof of concept now, but the point of showing a low-count bounce raytracing that still looks decent especially after denoising gives us a nice roadmap on the future. Maybe given time, we will move to this as the new standard or at least a probable alternate to baked lighting.

by Nathan Ayotte
12 hours ago

Fuck you I'm stuck in some bullshit game some dickhead thought would be exciting.

Renderman’s Implementation of the Marschner Hair Shader
13 October, 2017

FXGuide has recently published an amazing article on the technology behind Renderman’s implementation of the Marschner Hair shader. The article features interviews with both Professor Steve Marschner (Cornell University) and Christophe Hery (Pixar Research group).

Here is a small piece of the article to get you interested:

The success of the Marschner model is in great part due to the specular estimatation and it’s deployment of three specular lobes using multiple specular transport paths:

  • Primary Specular: This can be described as the specular reflection.
  • Secondary Specular: TRT “transmit” this becomes the colored specular contribution.
  • Transmit Specular: TT light transmits through the hair surface (forward scattering) and produces the important back lighting.
The Marschner spec model

The key contribution of that original paper was to “identify, explain, and verify these different modes of scattering in hair and the appearance characteristics they are responsible for, as well as to provide a simple model to simulate them” commented Marschner when he spoke recently to fxguide.

The components of the original (2003 model. The first three hair examples are circular hair (1) The primary highlight) alone; (2) the TRT component (secondary highlight) alone; (3) the combined model. The 4th example (right) is the same full model showing elliptical hairs with texture due to glints.


You can find the full article on FXGuide.

Source: FXGuide

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2 Comments on "Renderman’s Implementation of the Marschner Hair Shader"


wow that hair looks “Incredibles”…
And wind swept like a lil boy who could run “supers” fast?


I think Epic used a simplified model inspired by this for the anisotropic spec in Paragon hair as well?
But can’t seem to find that info? Anyone know otherwise?