Networked Virtual Environments

Abstract: INTRODUCTION The inherent need of humans to communicate acted as the moving force for the formation, expansion and wide adoption of the Internet. The need for communication and collaboration from distance resulted in the evolution of the primitive services originally offered (i.e. e-mail) to advanced applications, which offer a high sense of realism to the user, forming a reality, the so-called virtual reality. Even though virtual environments were first introduced as stand alone applications, which could run on a single computer, the promising functionalities of this new form of representation and interaction as well as the familiarity of the users with it drew increased research interest. This fact resulted in virtual reality to be viewed as the solution for achieving communication and collaboration between scattered users, in various areas of interest, such as entertainment, learning, training, etc. This led to the creation of Networked Virtual Environments (NVEs). In particular, NVEs were first introduced in the 80's and the first areas that exploited the newborn technology were military and entertainment applications. In particular, the U.S Department of Defense played an important role to the direction of applications, protocols and architectures for this promising technology. In the 90's, where academic networks became a reality, NVEs drew increased academic research interest and a variety of applications and platforms were developed. In particular, the academic community has reinvented, extended, and documented what the Department of Defense has done. The evolution and the results extracted by research on this field were widely adopted from multiple areas of interest, with main representative the entertainment area. Since 2000, where virtual reality technology, processing power of computers and the network were significantly improved, a wide variety of systems, protocols and applications were developed. In particular, the familiarization the end users with the Internet and the promising advantages and opportunities of Virtual Reality contributed to currently view NVEs as an effective tool for supporting communication and collaboration of scattered users. Currently, the application areas of NVEs have been widely expanded and their use can be found at military and nowadays tend to consist a powerful tool for communication and collaboration, with applications ranging from entertainment and teleshopping to engineering and medicine. To this direction, in the recent years important active research on this topic in both academic and industrial research is taking place.