Light Scattering from Human Hair Fibers
July 2003
in “
ACM Transactions on Graphics
”
New to Hair Fibers? There is a guide in the encyclopedia. Read the guide → human hair fibers light scattering Kajiya and Kay model specular highlights scattering hair fiber rotation transparent elliptical cylinder absorbing interior tilted scales surface reflection transmission internal reflection elliptical cross-section cuticle scales hair fiber roughness hair fibers light scattering specular highlights hair rotation transparent cylinder absorbing interior tilted scales surface reflection transmission internal reflection elliptical cross-section cuticle scales hair roughness
Studysummary In this study, a new shading model for hair was developed that better matches real-life light scattering, thanks to detailed new measurements of hair fiber scattering not predicted by existing models. Our plain-language summary of this paper — not a Tressless recommendation.
In 2003, researchers conducted a study on light scattering from human hair fibers, which led to the development of a new practical shading model for rendering hair in computer graphics. They discovered that the classic Kajiya and Kay model did not predict certain observed effects, such as multiple specular highlights and variations in scattering with the rotation of the hair fiber. The new model, based on a transparent elliptical cylinder with an absorbing interior and a surface of tilted scales, was able to qualitatively match the scattering behavior of real hair. The study involved detailed measurements using a four-axis goniometer and a CCD camera, and it accounted for surface reflection, transmission, and internal reflection, as well as the hair's elliptical cross-section and the tilt of cuticle scales. The model also considered the effects of hair fiber properties like roughness and cuticle scales, and it was filled in empirically for details not available from simple analysis. The researchers implemented the model in rendering software, producing images with 50,000-100,000 hair fibers, and suggested that for more realistic hair rendering, various scattering modes should be considered rather than relying on diffuse scattering alone. The findings have implications for both computer graphics and hair care product development.
