건축 마감재의 이방성반사율 측정 및 반사분포함수 수치모델 개발

Abstract

In using lighting simulation computer programs such as RADIANCE and Lightscape, accurate modelings of the Bidirectional Reflectance Distribution Functions(BRDFs) of surface materials are required. The BRDFs can be usually obtained by measuring the incident and reflected light intensities in terms of horizontal and vertical angles. Then, the measured bidirectional reflectance values need to be numerically modeled for lighting simulation programs which are based on the Monte Carlo method and ray-tracing technique.The purpose of this study was to develop and validate an apparatus to measure the bidirectional reflectance values of surface materials and a numerical model of BRDFs based on the measured reflectance values.In order to validate the developed apparatus, three different typical surface materials which have different reflection characteristics were measured in terms of bidirectional reflectance values. Then, a numerical model of BRDF was developed using the Bezier surface modeling algorithm, which can determine the bidirectional reflectance values for any given pair of incident and reflection angles.