An orientation update message filtering algorithm in collaborative virtual environments

Orientation update message filtering is an important issue in collaborative virtual environments (CVEs). Dead-reckoning (DR) is a known effective mechanism for update message filtering. Yet, previous dead-reckoning techniques mainly focus on the update message filtering for positions. The existing orientation dead-reckoning algorithms are based on fixed threshold values. The drawbacks of fixed thresholding for orientations (FTO) are discussed in this paper. We propose a variable thresholding for orientations (VTO) based on average recent angular velocity. The main advantage of the proposed VTO is the ability of balancing the number of state update messages and shift frequency of direction and speed of rotation. Mao-Jun Zhang received his B.E. and Ph.D. degrees in information system engineering from National University of Defense Technology, China, respectively in 1992, 1997. He was a faculity member in the Department of System Engineering and Mathematics, National University of Defense Technology from 1997 to 2001. He works as a postdoctoral researcher at Distributed and Collaborative virtual Environments Research Laboratory (DISCOVER), University of Ottawa, Canada from 2002. He has authored over 20 refereed papers and a graduate textbook. He is a member of IEEE and ACM. His recent research interests include collaborative virtual environments, multimedia information processing and grid-based visualization. Nicolas D. Georganas is a distinguished university professor and canada research chair in information technology, School of Information Technology and Engineering, University of Ottawa, Canada. He received the Dipl.Ing. degree in electrical engineering from the National Technical University of Athens, Greece, in 1966 and the Ph.D. degree in electrical engineering (Summa cum Laude) from the University of Ottawa in 1970. He is a fellow of IEEE, fellow of the Canadian Academy of Engineering, fellow of the Engineering Institute of Canada, and fellow of the Royal Society of Canada. In 2002, he received the Killam Prize for Engineering, Canada's highest award for career achievements in research. His research interests are multimedia communications, pervasive computing and collaborative virtual environments.