Hair Animation Methods

Rendering and animation of hair is a difficult task, mainly because of the complex physical properties of hair and the large number of primitives involved. Various physical models and simplification methods have to be adopted. This paper presents the current state of the art both in the field of hair animation and rendering, as well as a brief description of work in progress on a custom hair animation system. Introduction Realistic animation and rendering of hair is a crucial part of presenting virtual humans. Without natural-looking hair, realism of the presented image is severly hampered. Unfortunately, rendering hair realistically is a difficult process. A typical human has more than 100,000 individual hair strands. Hair is partially translucent and exhibits complex light reflection properties. Matters are complicated further by hair’s anisotropic nature; the length of a typical hair strand is several orders of magnitude larger than its diameter. The great number of individual strands and their fine structure is a severe complication for animation techniques as well. Hair strands are in constant contact and affect each other in many ways, including surface friction, lipid cohesion, static electricity etc. Constant contact of such a large number of sub-pixel primitives makes usage of explicit simulation and collision detection impossible. The primary purpose of this paper is to present a review of current approaches used in hair animation and rendering. It also outlines my work in progress on a custom animation system.