The extent to which the addition of haptic communication between human users in a shared virtual environment (SVE) contributes to the shared experience of the users has not received much attention in the literature. In this paper we describe a demonstration of and an experimental study on haptic interaction between two users over a network of significant physical distance and a number of network hops. A number of techniques to mitigate instability of the haptic interactions induced by network latency are presented. An experiment to evaluate the use of haptics in a collaborative situation mediated by a networked virtual environment is examined. The experimental subjects were to cooperate in lifting a virtual box together under one of four conditions in a between-groups design. Questionnaires were used to report the ease with which they could perform the task and the subjective levels of presence and copresence experienced. This extends earlier work by the authors to consider the possibility of haptic collaboration under real network conditions with a number of improvements. Using the technology described in this paper, transatlantic touch was successfully demonstrated between the Touch Lab at Massachusetts Institute of Technology, USA and Virtual Environments and Computer Graphics (VECG) lab at University College London (UCL), UK in 2002. It was also presented at the Internet II demonstration meeting in 2002 between University of Southern California and the Massachusetts Institute of Technology.

A virtual environment (VE) presents a complex problem with interesting nontrivial challenges for software development. The problems increase when considering VEs that are both distributed and shared among multiple participants. The majority of existing systems supporting large-scale VEs (LSVEs) are based on monolithic architectures, making maintenance and software reuse difficult at best. These problems have begun to be addressed by recent VE systems that employ software engineering principles in their design. Although modularity is addressed, many other issues remain unsolved, such as interoperability between different systems. The Java Adaptive Dynamic Environment (JADE) is presented as an alternative to the traditional approach for developing a core infrastructure for VE systems. JADE consists of a component framework along with a lightweight cross-platform kernel that permits system evolution at runtime and enables cross-system integration.