A local perception filter for distributed virtual environments

Dynamic multi-user interactions within a distributed collaborative virtual environment (CVE) suffer from abrupt state transitions due to communication delays-an action by one user only becoming apparent to another user after the delay. This results in a divergence of the environment for the duration of the delay, followed by an abrupt jump to resynchronise, so that the current state of the virtual world is displayed. Such discontinuities do not occur in the real world and thus appear unnatural and disconcerting to the users. This paper develops the concept of a 3 1/2 D perception model, as an alternative to prediction, which locally filters the underlying model, ensuring that each user views a continuous version of the environment, such that no jumps occur, despite delays arising from remote user interaction. Each user's 3 1/2 D filter is specific to their own circumstances, so that each user's perception of the environment is slightly different from that of other users.