Realistic real-time rendering of human face with environment lighting

Instead of simple point or area lights for illuminating human face in most rendering methods, we aim to render the appearance of human face influenced by surrounding environment lighting in some real scenes. In this paper, we accurately approximate the specular reflection by using the Kelemen/Szirmay-Kalos reflectance model and ten varying specular parameters over the whole face. Also, subsurface scattering can be well simulated with linear sum of Gaussian blurring in real-time. Further, we use the stretch-map texture to correct UV distortion problem result from blurring in the texture-space. Considering the environment lighting influence to appearance of human face, we use spherical harmonics to represent environment lighting and a quick occlusion approach to obtain a much more realistic rendering of human face, which make the human face look much more natural according to surroundings.