title: Split off-specular reflection and surface scattering from woven materials.
abstract: We measured radiance distributions for black lining cloth and copper gauze using the convenient technique of wrapping the materials around a circular cylinder, irradiating it with a parallel light source and collecting the scattered radiance by a digital camera. One family of parallel threads (weave or weft) was parallel to the cylinder generator. The most salient features for such glossy plane weaves are a splitting up of the reflection peak due to the wavy variations in local slopes of the threads around the cylinders and a surface scattering lobe due to the threads that run along the cylinder. These scattering characteristics are quite different from the (off-)specular peaks and lobes that were found before for random rough specular surfaces. The split off-specular reflection is due to the regular structures in our samples of man-made materials. We derived simple approximations for these reflectance characteristics using geometrical optics.
authors.affiliation: Helmholtz, Princetonplein 5, 3584 CC Utrecht, the Netherlands.
authors.forename: Sylvia C
authors.initials: SC
authors.lastname: Pont
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Koenderink