The computer synthesis of expressive three-dimensional facial character animation.

This present research is concerned with the design, development and implementation of three-dimensional
computer-generated facial images capable of expression
gesture and speech.
A review of previous work in chapter one shows that to date
the model of computer-generated faces has been one in which
construction and animation were not separated and which
therefore possessed only a limited expressive range. It is
argued in chapter two that the physical description of the
face cannot be seen as originating from a single generic
mould. Chapter three therefore describes data acquisition
techniques employed in the computer generation of free-form
surfaces which are applicable to three-dimensional faces.
Expressions are the result of the distortion of the surface
of the skin by the complex interactions of bone, muscle and
skin. Chapter four demonstrates with static images and short
animation sequences in video that a muscle model process
algorithm can simulate the primary characteristics of the
facial muscles.
Three-dimensional speech synchronization was the most
complex problem to achieve effectively. Chapter five
describes two successful approaches: the direct mapping of
mouth shapes in two dimensions to the model in three
dimensions, and geometric distortions of the mouth created
by the contraction of specified muscle combinations.
Chapter six describes the implementation of software for
this research and argues the case for a parametric approach.
Chapter seven is concerned with the control of facial
articulations and discusses a more biological approach to
these. Finally chapter eight draws conclusions from the
present research and suggests further extensions.

A Thesis submitted to Middlesex University in partial fulfilment of the equirements for the Degree of Doctor of Philosophy.