A multi-layered reflection model of natural human skin

The reflection model of human skin depends on the optical properties of its structural components, including a layer of naturally secreted sebum. Sebum is found over most parts of the body, causing skin to look more specular, depending on the viewing conditions. To capture the differences in appearance caused by the presence of sebum on skin surface, we have developed a three-layer simulation model. The resultant reflection model consists of the specular reflection due to the Fresnel effect, as well as the diffuse reflection from subsurface scattering. Optical and geometric properties are used as control parameters to influence the surface reflection and subsurface scattering of light within the three layers. The bi-directional reflectance distribution function obtained from the simulation is verified experimentally and used to render the natural appearance of human skin.