A few years ago, Virtual Reality
technologies and Virtual
Environments were seen by some as a panacea and the computer
interface of the
future. VR received a lot of attention in the media and devices such as
head mounted displays or data gloves have become widely recognised. Of
particular interest was the ability to realise a vision that had been
described in a number of science fiction novels: providing a parallel
world in which it would be possible to be present, interact and feel as
if in the real world. This vision is realised by Collaborative Virtual
Environments (CVEs). CVEs are three-dimensional computer-generated
environments where users are represented by avatars and can navigate
and interact in real-time independently of their physical location.
While the technology has not lived up to early expectations, real
niched applications and the success of networked games have shown its
viability and promises. This report summarises a number of the
technologies that are commonly used to interface with virtual
environments. Additionally, it presents some of the major CVE systems
to date and isolates a number of trends when it comes to network
architectures, protocols and techniques and to software choices.