Overview
Reflection by three different surface finishes on metal sheets shall be characterised and modelled to evaluate applicability in a building envelope relying on a particularly dark appearance. Gonio-photometric measurements on the three samples provide the photometric Bidirectional Reflectance Distribution Function (BRDF) for each finish. The BRDF describes reflection as a function of pairs of incident (toward the light source) and outgoing (reflected) directions. The measured BRTD is compiled into a compact data-driven model of adaptive directional resolution, that maintains the directional scattering around the mirror direction that is characteristic for any glossy surface.