Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Simulating facial expressions

Because the human face plays the most important role for identification and communication, realistic construction and animation of the face is of immense interest in the simulation of humans. Computer simulation of human facial expressions requires an interactive ability to create arbitrary faces and to provide a controlled simulation of expressions on these faces. The FACE software presents the interactive facilities for simulating abstract muscle actions using free-form deformations (FFD). The particular muscle action is simulated as the displacement of the control points of the control-unit for an FFD defined on a region of interest. One or several simulated muscle actions constitute a minimum perceptible action (MPA), which is defined as the atomic action unit to build an expression. In the FACE software, the skin surface of a human face, an irregular structure, is considered as a polygonal mesh. Muscular activity is simulated using rational free-form deformations. To simulate the effects of muscle actions on the skin of a human face, regions are defined on the facial mesh corresponding to the anatomical description of the regions of face where a muscle action is desired. A control lattice can then be defined on the region of interest. The deformations obtained by actuating muscles to stretch, squash, expand and compress the inside volumes of the facial geometry are simulated by displacing the control points of the control lattice. The region inside the control lattice deforms like a flexible volume, according to the displacement and the weight at each control point. The resulting software is subdivided into the following layers: Abstract Muscles, Minimum Perceptive Actions, Phonemes and Expressions, Expressions and Words.

Reported by

University of Geneva
Rue General-Dufour 24
1211 Geneva
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