II. BACKGROUND
3D Virtual Worlds are sophisticated platforms supporting a set of human activities, enriching the way we learn, work and socialize. Internet technologies and applications have facilitated the adoption of Virtual Worlds that allow for file sharing, virtual meetings, seminars/lectures and scientific experiments [8]. Due to limitations posed from communication networks, Virtual Worlds were restricted to a personal computer perspective of life [9]. The concept of reproducing an environment as a Virtual World was born in late ’80s. Reference [10] claimed that computers were powerful enough to implement cutting edge models of complicated physical environments. Moreover, [11] refer to Virtual Worlds in plural suggesting that a computer allows access to multiple virtual worlds and not a single one.