Modeling hair using level-of-detail representations

We present a novel approach for modeling hair using level-of-detail representations. The set of representations include individual strands, hair clusters, and hair strips. They are represented using subdivision curves or surfaces, and have the same underlying base skeleton to maintain consistent high-level physical behavior when a transition between different levels-of detail occurs. This framework supports automatic simplification of dynamic simulation, collision detection, and graphical rendering of animated hair. It also offers flexibility to balance between the overall performance and visual quality, and can be used to model and render different hairstyles. We have used these level-of-detail representations to animate various hairstyles and obtained noticeable performance improvement, with little loss in visual quality.

1 Introduction

The ability to model human features has become an essential aspect of 3D graphics for modeling avatars in virtual environments, virtual humans in computer games, and human characters in animated films. A human head can have over 100, 000 individual strands of hair. Animating hair in real-time is a challenging problem due to the high number of primitives required to model hair accurately and re-alistically. It is also difficult to achieve stable and robust simulation of hair dynamics as well as interactions among the hair and between the hair and the bodv for different tvnes of hairstvles.