The MERL BRDF database contains reflectance functions of 100 different materials. Each reflectance function is stored as a densely measured Bidirectional Reflectance Distribution Function (BRDF). Sample code to read the data is included with the database. Note that parameterization of theta-half has changed. Matusik, W., Pfister, H., Brand, M., McMillan, L., "A Data-Driven Reflectance Model", ACM