Modeling BRDF of Silk Fabric by Modifying Phong Reflection Model

摘要

The optical quality of silk fabric is mainly considered on its color and gloss. In this study, the BRDF (bidirectional reflectance distribution function) of silk fabrics was measured by a gonio-spectrophotometer. The measured BRDFs were analyzed in terms of diffuse and specular components. It was observed that silk fabric tends to reflect the diffuse component according to Phong reflection model. However, the specular component has off-specular characteristic. We modified Phong reflection model and proposed a new model by taking off-specular reflection of silk fabric into consideration. Then, the proposed model was evaluated and compared to Phong, Oren-Nayar, Ward and Ashikmin-Shirley reflection models. It is found that BRDF calculated by the proposed model had been fitted to the measured BRDF better than the other models.