Human Skin Modelling and Rendering

Creating realistic-looking skin is one of the holy grails of computer graphics and is still an active area of research. The problem is challenging due to the inherent complexity of skin and its variations, not only across individuals but also spatially and temporally among one. Skin appearance and reflectance vary spatially in one individual depending on its location on the human body, but also vary temporally with the aging process and the body state. Emotions, health, physical activity, and cosmetics for example can all affect the appearance of skin. The spatially varying reflectance of skin is due to many parameters, such as skin microand meso-geometry, thickness, oiliness, and pigmentation. It is therefore a daunting task to derive a model that will include all these parameters to produce realistic-looking skin. The problem is also compounded by the fact that we are very well accustomed to the appearance of skin and especially sensitive to facial appearances and expressions. Skin modelling and rendering is crucial for many applications such as games, virtual reality, films, and the beauty industry, to name a few. Realistic-looking skin improves the believability and realism of applications. The complexity of skin makes the topic of skin modelling and rendering for computer graphics a very difficult, but highly stimulating one. Skin deformations and biomechanics is a vast topic that we will not address in this dissertation. We rather focus our attention on skin optics and present a simple model for the reflectance of human skin along with a system to support skin modelling and rendering.