JVRC10: Joint Virtual Reality Conference of EGVE - EuroVR - VEC
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Item Automated Positioning of Annotations in Immersive Virtual Environments(The Eurographics Association, 2010) Pick, Sebastian; Hentschel, Bernd; Tedjo-Palczynski, Irene; Wolter, Marc; Kuhlen, Torsten; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteThe visualization of scientific data sets can be enhanced by providing additional information that aids the data analysis process. This information is represented by so called annotations, which contain descriptive meta data about the underlying visualization. The meta data results from diverse sources like previous analysis sessions (e.g. ideas, comments, or sketches) or automated meta data extraction (e.g. descriptive statistics). Visually integrating annotations into an existing data visualization while maintaining easy data access and a clear overview over all visible annotations is a non-trivial task. Several automated annotation positioning algorithms have been proposed that specifically target single-screen display systems and hence cannot be applied to immersive multiscreen display systems commonly used in Virtual Reality. In this paper, we propose a new automated annotation positioning algorithm specifically designed for such display systems. Our algorithm is based on an analogy to the well-known shadow volume technique, which is used to determine occlusion relations. A force-based approach is used to update annotation positions. The whole algorithm is independent of the specific annotation contents and considers well-established quality criteria to build an annotation layout. We evaluate our algorithm by means of performance measurements and a structured expert walkthrough.Item The Effect of Varying Path Properties in Path Steering Tasks(The Eurographics Association, 2010) Liu, Lei; Liere, Robert van; Torsten Kuhlen and Sabine Coquillart and Victoria InterrantePath steering is a primitive 3D interaction task that requires the user to navigate through a path of a given length and width. In a previous paper, we have conducted controlled experiments in which users operated a pen input device to steer a cursor through a 3D path subject to fixed path properties, such as path length, width, curvature and orientation. From the experimental data we have derived a model which describes the efficiency of the task. In this paper, we focus on studying the movement velocity of 3D manipulation path steering when one or more path properties vary during the task. We have performed a repeated measures design experiment of 8 scenarios, including a scenario in which all path properties were kept constant, 3 scenarios in which the path width, curvature and orientation varied, 3 scenarios of varying two path properties, and 1 scenario of varying all properties. The analysis of our experimental data indicates that a path of varying orientation or width results in a low average steering velocity. During a continuous steering, the joint where a change in path curvature or orientation takes place also significantly decreases the velocity. In addition, path width and curvature are highly-correlated to the average velocity of a segment, i.e. the wider a segment (or the smaller the path curvature), the larger the average steering velocity on that segment. The results of this work could serve as guidelines for designing higher level interaction techniques and better user interfaces for traditional HCI tasks, e.g. 2D or 3D nested-menu navigation.Item The Extended Window Metaphor for Large High-Resolution Displays(The Eurographics Association, 2010) Willert, Malte; Ohl, Stephan; Lehmann, Anke; Staadt, Oliver; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteWe present a novel tele-presence approach that extends the window metaphor by combining large high-resolution LCD walls with multi-camera 3D video. We propose to integrate an array of cameras into the bezels of the wall to support flexible camera placement for optimized video acquisition. The users's 3D video representation combined with the high-resolution LCD wall provides local and remote users with a shared virtual space in an extended life-size window metaphor. We discuss important system design aspects such as camera placement strategies, resolution, field of view, and dynamic camera selection for different 3D video reconstruction approaches, such as stereo and visual hulls. Finally, we describe our current prototype system based on the design guidelines described in this paper.Item A Further Assessment of Factors Correlating with Presence in Immersive Virtual Environments(The Eurographics Association, 2010) Phillips, Lane; Interrante, Victoria; Kaeding, Michael; Ries, Brian; Anderson, Lee; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteIn previous work, we have found significant differences in participants' distance perception accuracy in different types of immersive virtual environments (IVEs). Could these differences be an indication of, or consequence of, differences in participants' sense of presence under these different virtual environment conditions? In this paper, we report the results of an experiment that seeks further insight into this question. In our experiment, users were fully tracked and immersed in one of three different IVEs: a photorealistically rendered replica of our lab, a non-photorealistically rendered replica of our lab, or a photorealistically rendered room that had similar dimensions as our lab, but was texture mapped with photographs from a different real place. Participants in each group were asked to perform a series of tasks, first in a normal (control) version of the IVE and then in a stress-enhanced version in which the floor surrounding the marked path was cut away to reveal a two-story drop. We assessed participants' depth of presence in each of these IVEs using a questionnaire, recordings of heart rate and galvanic skin response, and gait metrics derived from tracking data, and then compared the differences between the stressful and non-stressful versions of each environment. Pooling the data over all participants in each group, we found significant physiological indications of stress after the appearance of the pit in all three environments, but did not find significant differences in the magnitude of the physiological stress response between the different environment conditions. However, we did find significant differences in the change in gait: participants in the photorealistic replica room group walked significantly slower, and with shorter strides, after exposure to the stressful version of the environment, than did participants in either the photorealistically rendered unfamiliar room or the NPR replica room conditions.Item Gesture Coordination in Collaborative Tasks through Augmented Feedthrough(The Eurographics Association, 2010) Simard, Jean; Ammi, Mehdi; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteThis article explores the use of haptic feedback for interpersonal communication in Collaborative Virtual Environments. The investigated approach enables the improvement of communication and coordination during closely coupled collaboration presenting several communication constraints (e.g., large and complex environments, distant collaboration, etc.). After the presentation of involved communication mechanisms, we propose the investigation of a low level communication approach through a haptic feedthrough mechanism. This channel is used to communicate kinematic information about a partner's gestures during closely coupled collaboration. Several communication metaphors, with complementary behaviors, were investigated to improve the coordination between two partners during an assembly task. The results clearly show the role of the proposed strategies for the improvement of gesture coordination and highlight the correlation between applied force and the level of coordinationItem Improving Photon Mapping Towards an Interactive Stage Lighting Framework(The Eurographics Association, 2010) Vierjahn, Tom; Meik, Stefan; Mostafawy, Sina; Bohn, Christian-A.; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteIn this work we present an improved rendering algorithm for the planning of stage lighting using photon mapping, since existing software implements algorithms that do not suit the lighting workflow in a theatre adequately. During theatre lighting, positional changes of light sources are occuring rarely compared to intensity and color changes: Once a light is positioned and aimed correctly, many intensity and color values are tested. Thus, intensity and color changes must be recomputed very fast whereas positional changes may take longer to be rendered. The algorithm we present provides such fast recalculations and furthermore balances idle times of user and renderer. In our algorithm image synthesis is split into a rendering and a real-time updating process. Additionally the wellknown concept of splitting the photon map into a global and a caustic map is consequently refined to light-specific photon maps and intensity buffers. The presented prototypic system utilizes general purpose API to get further insight into and proof of the concepts. Results indicate that the proposed algorithm can efficiently be used to plan and simulate stage lighting in a theatre.Item A New Adaptive Data Distribution Model for Consistency Maintenance in Collaborative Virtual Environments(The Eurographics Association, 2010) Fleury, Cédric; Duval, Thierry; Gouranton, Valérie; Arnaldi, Bruno; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteEnsuring that all the users see the same state of a Collaborative Virtual Environment (CVE) at the same time is very important to provide effective collaboration between these users. Absolute consistency is nearly impossible to achieve because it would prejudice the system responsiveness during user interactions. Consequently, existing solutions make a trade-off between consistency and system responsiveness according to their own requirements. We propose a new adaptive data distribution model that is able to dynamically change data distribution according to application requirements, user's actions and functions that virtual objects fulfill in the virtual environment. Our solutions can deal with several kinds of requirements imposed by various applications and network constraints. The choice of the data distribution can be made at the object level because all the objects of a virtual environment do not necessarily have the same need for consistency. Finally, we evaluate this model for collaborative scientific data visualization using a client/server architecture and HTTP/HTTPS connections. The results show that our model can minimize both interaction latency and gap in consistency between users, so it enables users to always perform real-time interactions in a consistent CVE.Item Short Paper: Approximating Distance Fields in Image Space(The Eurographics Association, 2010) Scheer, Fabian; Marschner, Mario; Müller, Stefan; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteFast proximity query algorithms are needed for a vast majority of computer graphics applications, ranging from visualization, simulation, animation, modelling, virtual and augmented reality to computer games. We present a novel and fast approach to approximate distance fields in image space at interactive frame rates. The vicinity of a point is sampled and the minimal distance to its surrounding geometry is determined based on the scenes depth values obtained by multiple stencil routed A-Buffers. Two sampling methods are compared with ground truth data in image space precision. Additionally, we introduce a method to determine the distance of an object to the next occluded object and a method to sample a directed distance field. The algorithms perform entirely on the GPU at interactive frame rates without the need for any precomputations and can handle dynamic content of arbitrary and deformable objects in massive data sets, making them feasible for a variety of applications.Item Short Paper: Design Tools, Hybridization Exploring Intuitive Interaction(The Eurographics Association, 2010) Wendrich, Robert E.; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteDesign and Design Engineering is about making abstract representations often based on fuzzy notions, ideas or prerequisite requirements with the use of various design tools. This paper introduces an interactive hybrid design tool to assist and support singular design activity or multiple collaborative creative processing and product creation. It enables the designer or design team to work smoothly with tangible artifacts and traditional design tools. It enables them to freely and intuitively manipulate these objects while simultaneously integrating the iterations into the virtual realm. By loosely-fitting the serendipitous objects, sketches, drawings, images and other data-sets of interest into the design creation process this hybrid tool supports the intuitive interaction and stimulates the immersive experience of augmented reality. The benefits of the system are haptic and intuitive physical interaction evoking the experience of augmented immersion during design activity. Furthermore the computational listing and repository of iterative history allows the users to access fallback choice-architecture and make full use of the hybrid environment and design synthesis capabilities.Item Short Paper: Engineering Realtime Interactive Systems: Coupling and Cohesion of Architecture Mechanisms(The Eurographics Association, 2010) Latoschik, Marc Erich; Tramberend, Henrik; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteThis paper reviews coupling and cohesion as software quality criteria for the development of Realtime Interactive Systems (RIS). The applicability of these criteria to evaluate RIS architecture mechanisms is examined while the utilization of existing software metrics is discussed. Three commonly found mechanisms, scene graphs, event systems and entity models, are evaluated with respect to a minimization of coupling and a maximization of cohesion. The paper motivates an analytical approach to the evaluation of software techniques as well as a strengthening of software technology aspects in the field of interactive simulations in general given current challenges of diversification, parallelization, and interconnection.Item Short Paper: Study of Synchronous and Colocated Collaboration for Search Tasks(The Eurographics Association, 2010) Simard, Jean; Ammi, Mehdi; Auvray, Malika; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteNowadays, Collaborative Virtual Environments offer new working methods allowing for the association of several experts in the same problem-solving process. These new platforms have the potential to improve the processing of complex environments with large dataflow and requiring different skills. This article proposes the investigation of a synchronous and colocated approach for a molecular design task. The aim of this research is to highlight the role and the contribution of Collaborative Virtual Environments for the improvement of complex tasks fulfillment.Item Short Paper: User Study for Mobile Mixed Reality Devices(The Eurographics Association, 2010) Braun, Anne; McCall, Rod; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteIn this paper we present a user study comparing four different mobile Augemented Reality (AR) interfaces. The focus of the study was on the usability of the devices, with respect to the unique nature of AR experiences, especially in the context of MR games, namely: the user usually needs at least one free hand; the interface might be used outside, the users will move around and they have to carry the equipment with them. The study found that Ultra Mobile PCs (UMPC) are preferred to Head Mounted Displays (HMD) and presents a number of concepts to the design of such systems.Item Short Paper: Virtual Storyteller in Immersive Virtual Environments Using Fairy Tales Annotated for Emotion States(The Eurographics Association, 2010) Alexandrova, Ivelina V.; Volkova, Ekaterina P.; Kloos, Uwe; Bülthoff, Heinrich H.; Mohler, Betty J.; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteThis paper describes the implementation of an automatically generated virtual storyteller from fairy tale texts which were previously annotated for emotion. In order to gain insight into the effectiveness of our virtual storyteller we recorded face, body and voice of an amateur actor and created an actor animation video of one of the fairy tales. We also got the actor's annotation of the fairy tale text and used this to create a virtual storyteller video. With these two videos, the virtual storyteller and the actor animation, we conducted a user study to determine the effectiveness of our virtual storyteller at conveying the intended emotions of the actor. Encouragingly, participants performed best (when compared to the intended emotions of the actor) when they marked the emotions of the virtual storyteller. Interestingly, the actor himself was not able to annotate the animated actor video with high accuracy as compared to his annotated text. This argues that for future work we must have our actors also annotate their body and facial expressions, not just the text, in order to further investigate the effectiveness of our virtual storyteller. This research is a first step towards using our virtual storyteller in real-time immersive virtual environments.Item Touching Floating Objects in Projection-based Virtual Reality Environments(The Eurographics Association, 2010) Valkov, Dimitar; Steinicke, Frank; Bruder, Gerd; Hinrichs, Klaus H.; Schöning, Johannes; Daiber, Florian; Krüger, Antonio; Torsten Kuhlen and Sabine Coquillart and Victoria InterranteTouch-sensitive screens enable natural interaction without any instrumentation and support tangible feedback on the touch surface. In particular multi-touch interaction has proven its usability for 2D tasks, but the challenges to exploit these technologies in virtual reality (VR) setups have rarely been studied. In this paper we address the challenge to allow users to interact with stereoscopically displayed virtual environments when the input is constrained to a 2D touch surface. During interaction with a large-scale touch display a user changes between three different states: (1) beyond the arm-reach distance from the surface, (2) at arm-reach distance and (3) interaction. We have analyzed the user's ability to discriminate stereoscopic display parallaxes while she moves through these states, i. e., if objects can be imperceptibly shifted onto the interactive surface and become accessible for natural touch interaction. Our results show that the detection thresholds for such manipulations are related to both user motion and stereoscopic parallax, and that users have problems to discriminate whether they touched an object or not, when tangible feedback is expected.