Virtual Multiverse: Interperception in Multiple Virtual Universes Rummenigge R. Dantas, Aquiles M. F. Burlamaqui, Samuel O. Azevedo, Julio C. P. Melo, Claudio A. Schneider, Josivan Xavier, Luiz M. G. Gonçalves Universidade Federal do Rio Grande do Norte DCA-CT-UFRN, Campus Universitário, Lagoa Nova, CEP 59.072-970, Natal, RN, Brazil Abstract - In this paper we propose a design and implementation of a collaborative virtual environment that supports virtual multiverse. With this, we are creating an infra-structure that allows the insertion of all possible and imaginable virtual worlds, allowing the coexistence of these different virtual worlds in a same application. On this system, the users can visit many different words using a same avatar. Keywords - Collaborative Virtual Environments, Multiverses, Consistency. I. INTRODUCTION Collaborative virtual environments are multi-user systems that provide communication, perception, and other ways of interaction in virtual worlds. A milestone in the development of these environments was the Habitat, launched in 1985 [1]. Since then, dozens of environments have been developed, each one with its own peculiarities that range from the architecture used in its implementation to the ambience or stile used in the modeling and definition of these environments. The choice of the architecture to be used in such systems is very important, since it defines characteristics like robustness and scalability, which are essential for CVEs. Robustness defines the capacity of the system to recovering in case of failures. On the other hand, scalability shows the capacity that these systems have to support large quantities of users connected at the same time. Most architectures used in the development of CVEs are based on the Client- Server [2] and Peer to Peer (P2P) [3] approaches; although there are hybrid architectures as well, with characteristics of booth [4]. Regarding the used environment, the real world (where we live) is not always represented in these environments. There are CVEs that recreate imaginary worlds, such as fantasy medieval worlds (http://www.runescape.com/), where the avatars (virtual representation of users) can be warriors, mages, and maidens. Also, there are futuristic worlds (http://www.eve-online.com/) among others. We noticed that, regardless the architecture used, each one of these systems gives support to a single world or universe, and an environment is separated of the others. We could not find in the literature any CVE that supports multiple worlds or universes within the same application. Then, a question that arises is how a system, where the users would create many worlds/environments, should be designed in order to allow that such universes would coexist and interact at the same application? To answer this question, we rely on the Multiverse theory [5], which presupposes the existence of multiple universes organized into a larger body called Multiverse. The project of a CVE structured and based on this theory is an answer to the question approached, and is what we define as Virtual Multiverse. By enabling the coexistence of many universes with different themes in the same application, we can attend the aspirations of a greater number of users. Restricting the themes would exclude users who do not have an identity with any of the environments. Accessibility is another characteristic of high importance in a system when we aim to reach large numbers of users. To overcome this, our proposed architecture allows the creation of virtual worlds that implement the concept of Interperception [9]. So the main contribution of the current work is the definition and implementation of the architecture for allowing interperception in virtual multiverses. II. RELATED WORK Several massive architectures can be found in the literature, as NPSNET [6], RING [2], MASSIVE [7], among others [3,4], that support multi-user systems. Although these architectures propose solutions that solve scalability issues, none of these solutions foresees the implementation of virtual multiverses. Such implementation requires special attention in situations at which different universes coexist with physical constants and laws working in distinct ways, for each environment, albeit there is the possibility of avatars created in one universe to visit the other universes. When traveling between these universes, an VECIMS 2009 - International Conference on Virtual Environments, Human-Computer Interfaces and Measurements Systems Hong Kong, China May 11-13, 2009 978-1-4244-3809-9/09/$25.00 ©2009 IEEE