look, what they wear, and how they behave.
Just as in social circles, clothing and acces-
sories remain important in the virtual world. Studies of user behaviour show that avatars
are not twins copying the physical and psychological features of their creator, but rather
they have their own personality. Users may use their computerised representatives to
project their fantasies, with pale geeks becoming muscled hunks, and so on. Studies have
been carried out on the types of personifications users prefer in visual chat environments.
Popular categories include real-face, animal, cartoon, evil, celebrity, seductive, and many more.
This section concentrates mainly on the creation of avatar personifications with human
features, the preferred appearance for agents carrying out the role of tour guides in virtu-
al museum environments. Personification means more than just placing the user's avatar
in the virtual space; it is also connected with tracking users' preferences and knowledge.
These technologies will develop rapidly in the following years, as they will be increas-
servers are also covered here.
Human avatars are either full-body or head-only animated computer images, which
may or may not be able to `speak' via TTS engines.They can be used for personal com-
munication (to read incoming e-mails) or in entertainment and leisure applications.The
development of human avatars has its roots in photogrammetry. Photosets, comprising a
full-body scan (or full front and full profile in the case of heads) are required as initial
data.The user is then guided to fix different data points on specified areas of the sets.The
data thus acquired are processed and used to modify a standard mesh, mapping a 3D
model.The result is a customised avatar based on a real person's digital image. Completed
with animation transformations, the image changes to produce facial expressions, and/or
gestures and other body movements. Modern avatars can be augmented allowing users to
add emotional expression capabilities.
Enhanced with text-to-speech technology, avatars can speak. Despite the last two
decades of advances in digitisation equipment, animation algorithms and computational
power, realistic human moving images are not yet possible. CGI graphics have evolved
sufficiently to allow moviemakers to assemble casts of entirely computer-generated actors
with human voices, as films like Final Fantasy:The Spirits Within (2001) demonstrate.
A crucial factor in the way an avatar is received by its users lies in the realism with
which it mimics human behaviour. Avatars do not convincingly resemble real humans,
and characteristics such as personal intonation and slang are not sufficiently realistic; but
the technology is maturing rapidly.
By employing such tools as Macromedia Flash in place of three-dimensional modelling
and video-realism, it is possible to create online characters which add a little more
humanity and interaction to multimedia applications and Web sites.
Avatars can be fairly easy to use and maintain once the software has been installed and
set up.The programs used to run avatars often include facilities for generating responses
101 The Neversoft/Activision video game Tony Hawk's Underground (2003,
http://www.activision.com/microsite/thug/thug.html) allows users to map their own faces on to their
computerised representatives, thus enhancing the immersiveness of the game. As one fan puts it, `There's no
doubt that your initial reaction to getting your face in the game will be, "Dude,That's ME!"'
(http://www.planettonyhawk.com/thug/info/preview/). Virtual Clones allows similar treatment in
applications ranging from computer games to movies and TV: http://www.virtualclones.com
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