Helmuth Trefftz

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The availability of inexpensive and powerful graphics cards as well as fast Internet connections make Networked Virtual Environments viable for millions of users and many new applications. It is therefore necessary to cope with the growing heterogeneity that arises from differences in computing power, network speed and users' preferences. This paper(More)
In this paper we explore to what degree shared viewpoints in three-dimensional collaborative virtual environments enable effective collaboration. The paper applies research on shared viewpoints and telepointers to 3D environments. A lightweight Java-based tool for creating collaborative virtual environments was developed and used in the study. The system is(More)
We propose a communication's architecture for scaling distributed environments, aimed at minimizing the number of required multicast groups. The fundamental idea is to approximate the area-of-interest of entities, which ideally would be round, with hexagonal cells, and then associate multicast groups to the cells only when necessary – i.e. when the discrete(More)
This article presents the first results of using an Augmented Reality (AR) tool, designed to support tutoring sessions in multi-variate calculus. The tool is used either in a face-to-face setting in which the instructor and the students are collocated or in a distance setting, in which the instructor and students are physically in remote places. The tool(More)
The use of Shared Virtual Environments is growing in areas such as multi-player video games, military and industrial training, and collaborative design and engineering. As a result, different mixes of computing power and graphics capabilities of the participating computers arise naturally as the variety of people/organizations sharing a virtual environment(More)
In this paper we report results of the use of a telepresence application in a simulated distance education setting. The application combines video-conference with a networked virtual environment in which the instructor and the students can experiment with virtual object in a collaborative manner. The teaching for Understanding (TFU) framework is used as the(More)