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The objective of this research project is to develop a user-friendly and cost-effective interactive input device that allows intuitive and efficient manipulation of 3D objects (6 DoF) in virtual reality (VR) visualization environments with flat projections walls. During this project, it was planned to develop an extended version of a laser pointer with multiple laser beams arranged in specific patterns. Using stationary cameras observing projections of these patterns from behind the screens, it is planned to develop an algorithm for reconstruction of the emitter’s absolute position and orientation in space. Laser pointer concept is an intuitive way of interaction that would provide user with a familiar, mobile and efficient navigation though a 3D environment. In order to navigate in a 3D world, it is required to know the absolute position (x, y and z position) and orientation (roll, pitch and yaw angles) of the device, a total of 6 degrees of freedom (DoF). Ordinary laser-based pointers when captured on a flat surface with a video camera system and then processed, will only provide x and y coordinates effectively reducing available input to 2 DoF only. In order to overcome this problem, an additional set of multiple (invisible) laser pointers should be used in the pointing device. These laser pointers should be arranged in a way that the projection of their rays will form one fixed dot pattern when intersected with the flat surface of projection screens. Images of such a pattern will be captured via a real-time camera-based system and then processed using mathematical re-projection algorithms. This would allow the reconstruction of the full absolute 3D pose (6 DoF) of the input device. Additionally, multi-user or collaborative work should be supported by the system, would allow several users to interact with a virtual environment at the same time. Possibilities to port processing algorithms into embedded processors or FPGAs will be investigated during this project as well.
Realism and plausibility of computer controlled entities in entertainment software have been enhanced by adding both static personalities and dynamic emotions. Here a generic model is introduced which allows the transfer of findings from real-life personality studies to a computational model. This information is used for decision making. The introduction of dynamic event-based emotions enables adaptive behavior patterns. The advantages of this new model have been validated with a four-way crossroad in a traffic simulation. Driving agents using the introduced model enhanced by dynamics were compared to agents based on static personality profiles and simple rule-based behavior. It has been shown that adding an adaptive dynamic factor to agents improves perceivable plausibility and realism. It also supports coping with extreme situations in a fair and understandable way.
Ziel des hier beschriebenen Forschungsprojekts war die Entwicklung eines prototypischen Fahrradfahrsimulators für den Einsatz in der Verkehrserziehung und im Verkehrssicherheitstraining. Der entwickelte Prototyp soll möglichst universell für verschiedene Altersklassen und Applikationen einsetzbar sowie mobil sein.
During visual exploration of a natural scene, saccades must be used to direct the fovea to areas of interest in the scene. During these saccades, images of objects will be streaming across the retina at hundreds of degrees per second. Despite this disjoint motion of the retina, the world does not appear disjoint or unstable, and motion blur during saccades is not apparent. Sensitivity to many visual stimuli is known to be reduced during a change in fixation compared to when the eye is still. For example, motion of a small object is harder to detect during a saccade than during a fixation. We asked whether this saccadic suppression generalises to suppression of motion of the entire visual scene. Eye movements were measured with a video-based eye tracker. Saccade-contingent translations of 0.4, 0.8, or 1.2 deg were imposed on wide-field-of-view images of natural scenes. The changes were seldom noticed during saccades and detection rate for the smallest translation was just 6.25%. Qualitatively, even when trans-saccadic scene changes were detectable, they were less disturbing than equivalent changes in the absence of a saccade.
In interactive graphics it is often necessary to introduce large changes in the image in response to updated information about the state of the system. Updating the local state immediately would lead to a sudden transient change in the image, which could be perceptually disruptive. However, introducing the correction gradually using smoothing operations increases latency and degrades precision. It would be beneficial to be able to introduce graphic updates immediately if they were not perceptible. In the paper the use of saccade-contingent updates is exploited to hide graphic updates during the period of visual suppression that accompanies a rapid, or saccadic, eye movement. Sensitivity to many visual stimuli is known to be reduced during a change in fixation compared to when the eye is still. For example, motion of a small object is harder to detect during a rapid eye movement (saccade) than during a fixation. To evaluate if these findings generalize to large scene changes in a virtual environment, gaze behavior in a 180 degree hemispherical display was recorded and analyzed. This data was used to develop a saccade detection algorithm adapted to virtual environments. The detectability of trans-saccadic scene changes was evaluated using images of high resolution real world scenes. The images were translated by 0.4, 0.8 or 1.2 degrees of visual angle during horizontal saccades. The scene updates were rarely noticeable for saccades with a duration greater than 58 ms. The detection rate for the smallest translation was just 6.25%. Qualitatively, even when trans-saccadic scene changes were detectible, they were much less disturbing than equivalent changes in the absence of a saccade.
GL-Wrapper for Stereoscopic Rendering of Standard Applications for a PC-based Immersive Environment
(2007)
In this contribution a machine vision inspection system is presented which is designed as a length measuring sensor. It is developed to be applied to a range of heat shrink tubes, varying in length, diameter and color. The challenges of this task were the precision and accuracy demands as well as the real-time applicability of the entire approach since it should be realized in regular industrial line production. In production, heat shrink tubes are cut to specific sizes from a continuous tube. A multi-measurement strategy has been developed, which measures each individual tube segment several times with sub pixel accuracy while being in the visual field. The developed approach allows for a contact-free and fully automatic control of 100% of produced heat shrink tubes according to the given requirements with a measuring precision of 0.1mm. Depending on the color, length and diameter of the tubes considered, a true positive rate of 99.99% to 100% has been reached at a true negative rate of > 99.7.
In the presented project, new approaches for the prevention of hand movements leading to hazards and for non-contact detection of fingers are intended to permit comprehensive and economical protection on circular saws. The basic principles may also be applied to other machines with manual loading and/or unloading. Two new detection principles are explained. The first is the distinction between skin and wood or other material by spectral analysis in the near infrared region. Using LED and photodiodes it is possible to detect fingers and hands reliable. With a kind of light curtain the intrusion into the dangerous zone near the blade can be prevented. The second principle is video image processing to detect persons, arms and fingers. In the first stage of development the detection of upper limb extremities within a defined hazard area by means of a computer based video image analysis is investigated.
A Bicycle Simulator Based on a Motion Platform in a Virtual Reality Environment - FIVIS Project
(2007)
Many modern computer games take place in urban environments. One important fact about such environments is that there are plenty of other people around who might react to whatever the user does. For example in the "FIVIS" project a bicycle simulator is developed that will serve (beside other applications) as an instrument for traffic education which strongly requires other traffic participants reacting to the users actions (see http://www.fivis.eu and [7]).
This contribution describes our current work on a general approach for an interactive agent system for urban environments.
For almost all modern means of transportation (car, train, airplane) driving simulators exist that provide realistic models of complex traffic situations under defined laboratory conditions. For many years, these simulators have been successfully used for drivers’ training and education and have considerably contributed to the overall road safety. Unfortunately, there is no such advanced system for the bicycle, although the number of bike accidents has been increasing against the common trend during the last decade. Hence the objective of this project is to design a real bicycle simulator that is able to generate any desired traffic situation within an immersive visualization environment. For this purpose the bike is mounted onto a motion platform with six degrees of freedom that enables a close-to-reality simulation of external forces acting on the bike. This system is surrounded by three projection walls displaying a virtual scenario.
A Low-Cost Based 6 DoF Head Tracker for Usability Application Studies in Virtual Environments
(2008)
In this paper we present an ongoing research work dedicated to a Virtual-Reality-based product customization application development. The work is addressing the problem of flexible and quick customization of products from a great number of parts. Our application is an effective instrument that can be simultaneously used by two users for rapid assembly tasks, allowing engineers and designers to work collaboratively. Furthermore, it is directly connected to a manufacturing environment, which is able to produce the product right after customization. In the paper we describe the architecture of the application, our interaction and assembly techniques, and explain how the system can be integrated into a manufacturing environment.
Video Surveillance is in the center of research due to high importance of safety and security issues. Usually, humans have to monitor an area and often they have to do this for 24 hours a day. Thus, it would be desirable to have automatic surveillance systems that support this job automatically. The system described in this paper is such an automatic surveillance system that has been developed to detect several dangerous situations in a subway station. This paper discusses the high-level module of the system. Herein, an expert system is used to detect events.
