Comparison of BSDF Reconstruction Methods for Rough Surfaces

Abstract

The work is devoted to the problem of reconstruction of a bi-directional scattering distribution functions (BSDF) for rough surfaces. The paper contains short overview of different methods and comparison of their results. The elements with rough surfaces are widely used in modern optical devices, for example, such as light guiding plates for illuminating system of displays, car dashboards, or luminaires. So, accurate and effective reconstruction of scattering properties of rough surfaces is important for visualizations tasks and generation of photorealistic images. Typically scattering properties of rough surface are described with help of BSDF. In some cases, BSDF can be just measured; however in many cases direct measurement is not sufficient. For example, if it is required to define BSDF inside of the material. Such measurement is impossible or too expensive because neither detector of the measuring device nor the light source can be placed inside the material. Therefore, a lot of different approaches to reconstruct BSDF for rough surfaces were developed. The approaches are based on both wave and ray optics and use different analytical and numerical solutions. A great variety of approaches results in the situation when you would like to know what method could be selected as more appropriate for the specific sample. This work investigates a bunch of perspective methods of BSDF reconstruction for surfaces of different roughness. The verification is based on numerical as well as visual comparison with real measured data. Finally, the general conclusions and recommendations are presented about what method and for what applications is more appropriate.