The measurement and modeling investigation on the spectral polarized BRDF of brass

Abstract

Bidirectional reflectance distribution function (BRDF) offers complete description of the visual appearance properties of materials including the spectral and spatial characteristics. Numerous studies on BRDF have been performed for its important role in computer graphics, remote sensing, object characteristics analysis, and other fields. A few of these studies focus on the spectral polarized BRDF, which contains more optical information of materials than the unpolarized BRDF and the polarized BRDF at single wavelength. In this paper, the spectral polarized BRDF measurement of brass is studied based on a self-designed device in visible light band. The influences of wavelength, angle, polarization of incident, and reflected light on the BRDF are discussed in detail. The results indicate that the effect of wavelength on BRDF depends on the color of the sample. The polarization of incident light has little influence on the variation tendency of BRDF versus incident zenith angle and wavelength. In addition, the exponential model of BRDF is built according to material surface characteristics. The fitting results show that the calculated values are in good agreement with the measured values at different incident zenith angles. This work may be beneficial to the study of optical properties and process design of brass.