Abstract

This paper develops a highly automated approach to constructing realistic, working models of human heads for use in animation. These physics-based models are anatomically accurate and may be made to conform closely to specific individuals. We begin by scanning a person with a laser sensor which circles around the head, acquiring detailed range and reflectance information. Next, an automatic conformation algorithm adapts a triangulated face mesh of predetermined topological structure to these data. The generic mesh, which is reusable with different individuals, reduces the range data to an efficient, polygonal approximation of the facial geometry and supports a high-resolution texture mapping of the skin reflectivity. The conformed polygonal mesh forms the epidermal layer of a new, physics-based model of facial tissue. An automatic algorithm constructs the multilayer synthetic skin and estimates an underlying rigid "skull" substructure with a jointed jaw. Finally, the algorithm inserts synthetic muscles into the deepest layer of the facial tissue. These contractile actuators, which emulate the primary muscles of facial expression, generate forces that deform the synthetic tissue into meaningful expressions. To increase realism, we include constraints to emulate tissue incompressibility and to enable the tissue to slide over the skull substructure without penetrating into it. The resulting animate models appear significantly more realistic than our previous physics-based facial models. Keywords: Physics-Based Facial Modeling, Facial Animation, Cylindrical Facial Scanning, Feature-Based Facial Adaptation, Texture Mapping, Discrete Deformable Models. 1

Citations