MPI-I-2004-4-001

We describe a tool for interactively designing virtual hairstyles. The underlying hair model is efficient enough to render different hairstyles in real time. One of the major problems of modeling human hair is the large number of hair strands in a hairstyle. Despite of increasing hardware and graphics performance, it is still difficult to display about 100,000 hair strands at a sufficient speed for real time applications. Our approach to this problem is to combine single hair strands to hair wisps. Each hair wisp is represented by a 2D triangle strip that is textured with color and alpha maps. To achieve a higher degree of realism, our modeling system takes into account both hair-head collisions and hair-hair collisions.