Measurement and analysis of reflection and subsurface scattering

On the surface of an opaque object, an incident ray reflects at the incident point. The property of the reflection is described by the bidirectional reflectance distribution function (BRDF) that is a four-parameter function. On the other hand, an incident ray to a translucent object scatters in the material. This phenomenon is called as subsurface scattering, and described by the bidirectional scattering surface reflectance distribution function (BSSRDF) that is a six-parameter function. The measurement and analysis of the BRDF and BSSRDF are important for a variety of applications such as computer graphics and inspection of painted surfaces. This talk introduces our two recent works. One is for measuring BRDFs of opaque objects using a special optical hardware. The other is for analyzing BSSRDFs of translucent objects in the framework of the inverse rendering. Multiplexed Illumination for Measuring BRDF using an Ellipsoidal Mirror and a Projector[1] Measuring a bidirectional reflectance distribution function (BRDF) requires long time because a target object must be illuminated from all incident angles and the reflected light must be measure