January 31, 1994
This paper presents Langwidere, a facial animation system. Langwidere is the basis for a flexible system capable of imitating a wide range of characteristics and actions, such as speech or expressing emotion. Langwidere integrates a hierarchical spline modeling system with simulated muscles based on local area surface deformation. The multi-level shape representation allows control over the extent of deformations, at the same time reducing the number of control vertices needed to define the surface. The head model is constructed from a single closed surface allowing the modeling of internal structures such as tongue and teeth, rather than just a mask. Simulated muscles are attached to various levels of the surface with more rudimentary levels substituting for bone such as the skull and jaw. The combination of a hierarchical model and simulated muscles provides precise, flexible surface control and supports easy generation of new characters with a minimum of recoding.