Chiang, Matt Jen-YuanBitterli, BenediktTappan, ChuckBurley, BrentJoaquim Jorge and Ming Lin2016-04-262016-04-2620161467-8659https://doi.org/10.1111/cgf.12830We present an energy-conserving fiber shading model for hair and fur that is efficient enough for path tracing. Our model adopts a near-field formulation to avoid the expensive integral across the fiber, accounts for all high order internal reflection events with a single lobe, and proposes a novel, closed-form distribution for azimuthal roughness based on the logistic distribution. Additionally, we derive, through simulation, a parameterization that relates intuitive user controls such as multiple-scattering albedo and isotropic cylinder roughness to the underlying physical parameters.Computer Graphics [I.3.7]Three Dimensional Graphics and RealismShading10.1111/cgf.12830275-283