Survey of state melding in virtual worlds

The fundamental goal of virtual worlds is to provide users with the illusion that they are all seeing and interacting with each other in a consistent world. State melding is the core of creating this illusion of a shared reality. It includes two major parts: consistency maintenance and state update dissemination. Well-designed state melding technologies are also critical for developing a virtual world that can scale to a large number of concurrent users and provide satisfying user experiences. In this article, we present a taxonomy of consistency models and categorization of state update dissemination technologies for virtual worlds. To connect theories and practices, we then apply the taxonomy to case study several state-of-the-art virtual worlds. We also discuss challenges and promising solutions of state melding in large-scale virtual worlds. This survey aims to provide a thorough understanding of existing approaches and their strength and limitations and to assist in developing solutions to improve scalability and performance of virtual worlds.