Azimuthal Scattering from Elliptical Hair Fibers

The document from April 3, 2017, presents a comprehensive study on the scattering of light from elliptical hair fibers, which are shown to behave differently from circular fibers. The authors developed a new scattering model that accounts for the elliptical shape of hair fibers, introducing an Azimuthal Scattering Function (ASF) and a Bidirectional Curve Scattering Distribution Function (BCSDF) that are energy conserving. They found that elliptical fibers exhibit complex scattering behaviors, including a new ideal-specular forward-scattering behavior called the E mode, which was not predicted by previous models. The study involved detailed measurements and comparisons between the new model and actual hair fibers, revealing that the elliptical model provides a more accurate and realistic representation of hair appearance, especially in rendering bright, glittery highlights. However, the study also notes that further improvements are needed to fully capture all observed scattering phenomena. The research was supported by the National Science Foundation and the Intel Science and Technology Center for Visual Computing and was published in the ACM Transactions on Graphics.