i
i
i
i
i
i
i
i
2 1. Introduction
The value of this body of work, and of others in this field, requires no
explanation in the context of facial animation.
The ability to model the human face and then animate the subtle nu-
ances of facial expression remains a significant challenge in computer graph-
ics. Despite a heavy reliance on traditional computer graphics algorithms
such as modeling and rendering, facial modeling and animation are still be-
ing defined, without broadly accepted solutions. Facial animations often are
developed with ad-hoc techniques that are not easily extendible and that
rapidly become brittle. Therefore, this book presents a structured approach,
by describing the anatomy of the face, working though the fundamentals of
facial modeling and animation, and describing some state-of-the-art tech-
niques.
1.1 About This Book
Two-dimensional facial character animation has been well defined over the
years by traditional animation studios such as Disney Studios, Hanna-
Barbera, and Warner Brothers. However, three-dimensional computer-
generated facial character animation is not as well defined. Therefore, this
book is focused principally on realistic three-dimensional faces.
The purpose of this book is to provide a source for readers interested in
the many aspects of computer-based facial animation. In this book we have
tried to capture the basic requirements for anyone wanting to animate the
human face, from key framing to physically based modeling. The nature
of the subject requires some knowledge of computer graphics, although a
novice to the subject also can find the book an interesting resource about
the face.
Clearly, the field of computer-generated facial animation is rapidly chang-
ing; every year, new advances are reported, making it difficult to capture the
state of the art. However, it is clear that facial animation is a field whose
time has come. The growth of increasingly complex computer-generated
characters demands expressive, articulate faces. Most of the techniques em-
ployed today involve principles developed in the research community some
years ago—in some instances, more than a couple of decades ago.
So why this surge of interest in computer-generated facial animation?
There is no single reason, although we can point to several key influences.
Perhaps the strongest interest comes from the commercial animation stu-
dios, whose insatiable appetite for the latest and greatest visual effect is
both enormous and endless. These studios are trendsetters who popularize
new animation techniques. DreamWorks and Pixar are examples of such
production studios where, for example, the movies Shrek and The Incredi-
bles were produced. In addition, the advance in realism of video games has
demanded expressive facial animation with high levels of realism.
剩余445页未读，继续阅读
