Symmetric and asymmetric action integration during cooperative object manipulation in virtual environments

Cooperation between multiple users in a virtual environment (VE) can take place at one of three levels. These are defined as where users can perceive each other (Level 1), individually change the scene (Level 2), or simultaneously act on and manipulate the same object (Level 3). Despite representing the highest level of cooperation, multi-user object manipulation has rarely been studied. This paper describes a behavioral experiment in which the piano movers' problem (maneuvering a large object through a restricted space) was used to investigate object manipulation by pairs of participants in a VE. Participants' interactions with the object were integrated together either symmetrically or asymmetrically. The former only allowed the common component of participants' actions to take place, but the latter used the mean. Symmetric action integration was superior for sections of the task when both participants had to perform similar actions, but if participants had to move in different ways (e.g., one maneuvering themselves through a narrow opening while the other traveled down a wide corridor) then asymmetric integration was superior. With both forms of integration, the extent to which participants coordinated their actions was poor and this led to a substantial cooperation overhead (the reduction in performance caused by having to cooperate with another person)

Interactive Scientific Visualisation A Position Paper

This paper summarises the author's views on current developments in interactive scientific visualisation. It is based on a talk presented at the Eurographics '89 conference, held in Hamburg in September 1989. The paper takes issue with the direction of some current work and identifies areas where new ideas are needed. It has three main sections: data presentation methods, current visualisation system architectures, and a new approach based on parallel processing. 1 Introduction The upsurge of interest in visualisation was given a major impetus by a report prepared for the National Science Foundation in the USA (the ViSC report) [16]. The main thrust of this was to examine how the USA could remain competitive in this area, and therefore what research should be funded by the government. A major problem identified was how researchers could assimilate the truly vast amounts of data being poured out by supercomputers --- what the report termed "firehoses of data". The report recommended a s..

The Use of Virtual Reality for Training Process Plant Operatives

This paper describes an on-going collaborative project between CADCentre Ltd and the Advanced Interfaces Group (AIG) at the University of Manchester. From an industrial perspective, the main aim of the project is to explore the application of virtual reality techniques to the task of creating, and subsequently using, CAD models of complex process plants, such as oil rigs, oil refineries or power plants. For the academic partners, the goals are to understand and overcome problems of applying such techniques to large, real-world systems, and to research software architectures and algorithms which will underpin future developments in the design and application of virtual reality. Computer-aided process plant desig

Dynamic primitive caching for haptic rendering of large-scale models

In this paper we present a software approach to managing complexity for haptic rendering of large-scale geometric models, consisting of tens to hundreds of thousands of distinct geometric primitives. A secondary client-side caching mechanism, exploiting partitioning, is used to dynamically update geometry within the locality of a user. Results show that the caching mechanism performs well, and that graphical rendering performance becomes an issue before the caching mechanism fails. The performance penalty of the caching technique was found to be dependent on the type of partitioning method employed

Interactive reconstruction of virtual environments from video sequences

There are many real-world applications of Virtual Reality requiring the construction of complex and accurate threedimensional models that represent real environments. In this paper, we describe a rapid and robust semi-automatic system that allows such environments to be quickly and easily built from video sequences captured with standard consumer-level digital cameras. The system combines an automatic camera calibration algorithm with an interactive model-building phase, followed by automatic extraction and synthesis of surface textures from frames of the video sequence. The capabilities of the system are illustrated using a variety of example reconstructions