CONTACT: Arbitrary in-between motions for collision detection

A new approach to the collision detection problem was introduced in [8], that allows to detect collisions continuously and eciently between polyhedral primitives (vertices, edges and faces). This paper extends the results of [8] to continuously detect collisions between pairs of complex polyhedral objects. A C++ library, CONTACT, has been developped. The tests of this library, reported here, seem to show that this approach is especially suited for precise real-time interaction in virtual environments.

Tangible controllers for 3D widgets

We have used a tangible input device to control 3D widgets in a 3D VR environment. This can be a more efficient input method than unrestricted 6-DOF manipulation, since many 3D widgets impose some restrictions on how they can be manipulated. In particular for tasks that are in essence two-dimensional, such as drawing a contour on a surface, tangible controllers have advantages over unrestricted devices. This is especially useful in 3D environments which do not offer 2D input, such as the CAVE. We have combined the tangible controller with a 3D Magic Lens style visualization technique. We have conducted a small user study, in which we compare different input methods for drawing a contour on a three-dimensional curved surface using a 3D contour widget

Les Mammifères du département de la Loire. I. Rongeurs et Insectivores

In the department of Loire (France), six natural districts can be distinguished : four of them are old mountains, the two other ones are large plains, so the climate and the vegetation show many differences from one to another. Consequently, 31 species of micromammals (except Chiroptera) have been observed. These are principally medio-european species, but some mediterranean ones inhabit the southern range of the massif of Pilat. The relevance of the use of Barn Owl preys as a sampling method for the study of micromammals populations is then discussed according to the biogeographical scale.Le département de la Loire est très hétérogène ; formé de six districts naturels très contrastés, il constitue un terrain d'étude biogéographique privilégié. Corrélativement à l'existence de milieux variés, le peuplement micromammalien (Chiroptères exceptés) est particulièrement riche et diversifié (31 espèces), seules quelques espèces «montagnardes» manquent à notre inventaire. Une discussion sur notre technique d'étude, analyse des proies de Chouette effraie, complète cette synthèse départementale.Aulagnier S., Coquillart Hervé, Brunet-Lecomte Patrick. Les Mammifères du département de la Loire. I. Rongeurs et Insectivores. In: Bulletin mensuel de la Société linnéenne de Lyon, 52ᵉ année, n°4, avril 1983. pp. 94-104

Eurographics Symposium on Virtual Environments (2004)

In this paper, a new pattern based optical tracking method is presented for the recognition and pose estimation of input devices for virtual or augmented reality environments. The method is based on pencils of line fiducials, which reduces occlusion problems and allows for single camera pattern recognition and orientation estimation. Pattern recognition is accomplished using a projective invariant property of line pencils: the cross ratio. Orientation is derived from single camera line-plane correspondences, and position estimation is achieved using multiple cameras. The method is evaluated against a related point based tracking approach. Results show our method has lower latency and comparable accuracy, and is less sensitive to occlusion

Virtual Realities (Dagstuhl Seminar 13241, June 9-14, 2013)

This report documents the program and the outcomes of Dagstuhl Seminar 13241 "Virtual Realities". The main goal of the five day seminar was to bring together leading experts and promising young researchers to discuss current challenges and future directions in the field of virtual and augmented reality. The seminar was organized as series of individual presentations and seven working groups. Abstracts of the presentations and working group reports are collected in this report

Eurographics Symposium on Virtual Environments (2004), pp. 1--9 S. Coquillart, M. Gbel (Editors)

Creative and innovative people have good ideas for new kind of Mixed Reality applications. Applications designed by artists for example could enrich the exhibitions of modern museums. Developing such an application is a complex task, which nowadays is solved by software engineers. A component based authoring tool allows artists to develop applications by their own. We have developed an authoring tool, which integrates an user-friendly and intuitive calibration tool for a multi-marker detection system. We stabilize the orientation and position output of the marker tracking system by a filtering mechanism. We have decided to use a mobile device as the application platform to provide users a very flexible system

Changes in Navigational Behaviour Produced by a Wide Field of View and a High Fidelity Visual Scene Abstract

The difficulties people frequently have navigating in virtual environments (VEs) are well known. Usually these difficulties are quantified in terms of performance (e.g., time taken or number of errors made in following a path), with these data used to compare navigation in VEs to equivalent real-world settings. However, an important cause of any performance differences is changes in people’s navigational behaviour. This paper reports a study that investigated the effect of visual scene fidelity and field of view (FOV) on participants ’ behaviour in a navigational search task, to help identify the thresholds of fidelity that are required for efficient VE navigation. With a wide FOV (144 degrees), participants spent significantly larger proportion of their time travelling through the VE, whereas participants who used a normal FOV (48 degrees) spent significantly longer standing in one place planning where to travel. Also, participants who used a wide FOV and a high fidelity scene came significantly closer to conducting the search "perfectly " (visiting each place once). In an earlier real-world study, participants completed 93 % of their searches perfectly and planned where to travel while they moved. Thus, navigating a high fidelity VE with a wide FOV increased the similarity between VE and real-world navigational behaviour, which has important implications for both VE design and understanding human navigation. Detailed analysis of the errors that participants made during their non-perfect searches highlighted a dramatic difference between the two FOVs. With a narrow FOV participants often travelled right past a target without it appearing on the display, whereas with the wide FOV targets that were displayed towards the sides of participants overall FOV were often not searched, indicating a problem with the demands made by such a wide FOV display on human visual attention