Pieter Jorissen

A multi-user framework supporting video-based avatars

In this paper we present our ongoing work in setting up a multi-user framework that supports video texturing on avatars, creating added value for both gaming and collaborative work applications. Limiting the data propagation and bandwidth usage is a key goal when targeting a scalable application that will be deployed on a general-purpose network such as the Internet. We therefore present a number of techniques that can be used in these circumstances, including increased client responsibilities and multicast communications. By making full use of the increased client processing power and bandwidth, we can relieve the server of many of its traditional roles. At the same time, we can target a range of network-enabled devices by handing over control of quality parameters to the individual clients. Through the combination of real-time video distribution and animated avatars, we aim to achieve an increased level of immersion in the virtual world.

Dynamic interactions in physically realistic collaborative virtual environments

This work describes our efforts in creating a general object interaction framework for dynamic collaborative virtual environments. Furthermore, we increase the realism of the interactive world by using a rigid body simulator to calculate all actor and object movements. The main idea behind our interactive platform is to construct a virtual world using only objects that contain their own interaction information. As a result, the object interactions are application independent and only a single scheme is required to handle all interactions in the virtual world. In order to have more dynamic interactions, we also created a new and efficient way for human users to dynamically interact within virtual worlds through their avatar. In particular, we show how inverse kinematics can be used to increase the interaction possibilities and realism in collaborative virtual environments. This results in a higher feeling of presence for connected users and allows for easy, on-the-fly creation of new interactions. For the distribution of both the interactive objects and the dynamic avatar interactions, we keep the network load as low as possible. To demonstrate the effectiveness of our techniques, we incorporate them into an existing CVE framework.

A Framework Supporting General Object Interactions for Dynamic Virtual Worlds

This work introduces a new interaction framework for dynamic virtual environments. The proposed system is designed to deal with all possible interactions in a virtual world. The idea is to build up a world of objects that contain their own interaction information. As a result the object interactions are application independent and a single scheme is required to handle all interactions in the virtual world. Furthermore, an object model description is designed that provides a means to describe the object’s functionality. This description can also be used by AI agents to plan or execute interactions with these objects.

Bringing haptics and physical simulation together: haptic travel through physical worlds

This paper describes our efforts in bringing haptics closer to current dynamic virtual environments (VE). These interactive 3D worlds make more and more use of physical simulations in order to increase realism. As a first step in closing the gap, we propose haptic travel that allows users to feel how their virtual representation navigates through the simulated world. In this work, we show how we coupled stable haptic rendering to physical simulation in order to achieve this. By generating a force feedback field, based on the users input in combination with collision information provided by a rigid body simulator, we managed to provide the user with useful information on what is happening to its virtual representation. A humanoid animated character, which represents the user, is coupled to the rigid body object that represents the user in physical space. This character is animated according to the travel motions that the physical object makes, depending on user input from the haptic device. Our approach is suitable for a whole set of applications and input devices and can reduce the number of devices necessary to interact in VEs. Copyright

A virtual interactive community platform supporting education for long-term sick children

Analysis of existing iCT-based solutions for the education of long-term ill children reveal several weaknesses with respect to social and cooperative involvement, cost of development, and mobility issues. We present a scalable and affordable solution that supports both the social needs and learning process of these children. An educational platform was created based on the concepts of 3D networked virtual environments and Virtual interactive Communities. in this work we describe the system architecture, network setup and protocols, and how we implemented the educational support. Our solution incorporates innovative hardware, software and connectivity features, set in a user friendly user interface based on networking and 3D technologies. it helps to establish high quality involvement of the long-term sick children in a communication based scenario between the place where the child stays/has been moved and their original classroom learning setting.

Evaluating the Effects of Haptics on Presence while Traveling in a Desktop Virtual Environment

Virtual reality applications seek to fully immerse participants into their virtual world experience. The investigation of how stimuli on the different senses influence the users is therefore crucial. As navigation is one of the most ubiquitous tasks in virtual environments, studying the influence of haptics on user presence is a necessity for future applications. This work presents an empirical study on the role of haptics during travel in a desktop virtual environment. Three techniques were compared in respect to task performance, perceived task performance, perceived presence and mental and physical workload. While our results indicate that haptics has a positive influence on participant’s perceived presence and performance, his total workload remains constant. Furthermore, we show that these findings apply to both experienced and unexperienced virtual environment users.