Evaluation of Bidirectional Reflectance Distribution Function in the Process of Total Appearance Capture

Bidirectional reflection distribution function (BRDF) is a function that describes the optical properties of the object surface, which reflects the reflection characteristics of the object surface under different angles, light source direction and observation direction. The research of BRDF has important theoretical and practical value in the fields of computer graphics, computer vision, optics, and could be used to describe surface materials in the real world. Currently, much work has been done on measurement methods, measurement equipment and new measurement models, but limited work has been done on evaluating BRDF. We used an advanced material acquisition equipment-Total Appearance Capture (TAC), The two BRDF models used in this device, Ward model and GGX model, were comprehensively evaluated with comparison function, fitting time and data volume to compare the fitting ability of two different BRDF models for different materials. And the amount of data volume of the two models and the speed of fitting time.