Eugene d’Eon | Guillaume Francois | Martin Hill | Joe Letteri | Jean-Marie Aubry
Weta Digital
Eurographics Symposium on Rendering 2011


We present a reflectance model for rough dielectric cylinders such as human hair fibers.  Our model is energy conserving and can evaluate arbitrarily many orders of internal reflection.  Accounting for compression and contraction of specular cones produces a new longitudinal scattering function which is non-Gaussian and includes an off-specular peak.  Accounting for roughness in the azimuthal direction leads to an integral across the hair fiber which is efficiently evaluated using a Gaussian quadrature.  Solving cubic equations is avoided, caustics are included in the model in a consistent fashion, and more accurate colors are predicted by considering many internal pathways.

Discussion and Reviews

We include additional information about stable numerical evaluation of one of the component functions of the model here:
Publon 2803




  1. Working With the New Standard Hair Shader in Arnold 5 - Lesterbanks
    May 29, 2017

    […] can do this largely because new shader is based on the d’Eon model for specular and Zinke model for calculating diffuse. The shaders accounts for not one, but two types of […]

  2. Creación de pelo en Arnold 5 — Zao3D
    February 26, 2019

    […] 5, es el de Standard Hair. Es un shader físicamente correcto y está basado en el modelo d’Eon para los especulares y en el modelo Zinke para el difuso. Los resultados son muy realistas gracias […]