IPT/EGVE 2003: 7th International Workshop on Immersive Projection Technology, 9th Eurographics Workshop on Virtual Enviroments

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https://diglib.eg.org/handle/10.2312/374

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3D input devices and interaction concepts for optical tracking in immersive environments
(The Eurographics Association, 2003) Stefani, Oliver; Rauschenbach, Jörg; Andreas Kunz and Joachim Deisinger
In this poster abstract we present an interaction concept and input devices for optical tracking in virtual immersive environments. Requirements to input devices for immersive environments will be based on a document, outlining major requirements for VR-systems. A preliminary testing of the usability will be discussed. We conclude this abstract by presenting our interim findings.
Advancements in 3D Interactive Devices for Virtual Environments
(The Eurographics Association, 2003) Wormell, D.; Foxlin, E.; Andreas Kunz and Joachim Deisinger
New commercially available interactive 3D tracking devices and systems for use in virtual environments are discussed. InterSense originally introduced the IS-900 scalable-area hybrid tracking system for virtual environments in 1999. In response to customer requests, we have almost completely revamped the system over the past two years. The major changes include a drastic 3-fold reduction in the size and weight of the wearable sensor devices, introduction of wireless tracking capability, a standardized I2C interface to allow OEM system integrators to add additional custom controls, and evolution of the system software interfaces, the performance, and the price. This paper will briefly describe the underlying technology changes that have allowed these advances to occur, and will outline some of the configuration possibilities that are now supported. Specific examples of how these devices and systems are being used to improve productivity in oil & gas seismic analysis & well field planning; automotive design & test; and, industrial/military training applications will be used to illustrate. Customization standards and future developments are discussed.
An Affordable Optical Head Tracking System for Desktop VR/AR Systems
(The Eurographics Association, 2003) Mulder, Jurriaan D.; Jansen, Jack; Rhijn, Arjen van; Andreas Kunz and Joachim Deisinger
We present an affordable optical head tracking system for desktop-like VR/AR environments. The generic and specific head tracking requirements for these type of environments are defined, as well as the relaxations such environments put on head tracking systems. The presented head tracker is based on two low-cost, commodity FireWire cameras that track a simple 3D dot pattern. It is shown that the tracker provides high accuracy, an update rate of 30 updates per second, a low computational load, and a moderate delay of 66 ms. It is competitive to commercially available, moderate-cost head tracking systems yet for substantially lower costs.
Application Scenarios for Scientific Visualization and Virtual Reality Using a CAVE Infrastructure
(The Eurographics Association, 2003) Stern, Ch.; Noser, H.; Weissmann, J.; Stucki, P.; Andreas Kunz and Joachim Deisinger
Today s Virtual Reality applications require a high degree of immersion. This may be achieved by using a CAVE incorporating powerful 3D computer graphics workstations, panoramic multiple screen displays and projection walls, stereovision and interaction devices such as trackers and data gloves. This article describes Virtual Reality applications from the fields of scientific visualization in medicine and education embedded within the Blue-C environment, a state-of-the-art CAVE infrastructure.
Architecture of the virtual training system for buoyancy control
(The Eurographics Association, 2003) Korosec, Dean; Slavinec, Mitja; Bernad, Dani; Kolaric, Primoz; Prnaver, Katja; Andreas Kunz and Joachim Deisinger
In this paper we present the structure of the simulator which would allow diving beginners to experience the effect of buoyancy control mechanisms before actually entering the water.We believe such training would be less stressful and safer for all participants, but it should also reduce the time in water needed to manage basic practical diving skills. Central design requirements for the system were: realistic modelling of diving physics, various options of man-machine interface and possibility of immersion. With future studies we plan to clarify to what extent the immersive VR interfaces are able to further improve the diving training experience.
Augmented Reality for manufacturing planning
(The Eurographics Association, 2003) Doil, F.; Schreiber, W.; Alt, T.; Patron, C.; Andreas Kunz and Joachim Deisinger
The shortening of development cycles demand for efficient methods and tools for the planning of complex production systems. Recently immersive Virtual Reality technologies have been introduced to the manufacturing planning functions. This has lead to a decrease in planning times as well as to the improvement of the quality of planning results. The introduction of various virtual planning tools is targeting the complete integration of all planning tasks and demands an intuitive interaction with complex computer models of machinery, factorylayouts etc. Known methods and tools are limited to a purely virtual representation of planning objects and thus require the complete modeling of the production system. The high costs reduce the possible benefits of these tools and this technology in general. New potential for the improvement of the industrial planning process are offered by the AR-technology. Using AR-techniques an physically existing production environment can be superimposed with virtual planning objects. Planning tasks can thus be validated without modeling the surrounding environment of the production site. In this contribution we discuss the support of manufacturing planning tasks with the Augmented Reality technology. We present potential benefits and describe the development of an prototypical AR-System for the support of planning tasks.
Automated Testing of Virtual Reality Application Interfaces
(The Eurographics Association, 2003) Bierbaum, Allen; Hartling, Patrick; Cruz-Neira, Carolina; Andreas Kunz and Joachim Deisinger
We describe a technique for supporting testing of the interaction aspect of virtual reality (VR) applications. Testing is a fundamental development practice that forms the basis of many software engineering methodologies. It is used to ensure the correct behavior of applications. Currently, there is no common pattern for automated testing of VR application interaction. We review current software engineering practices used in testing and explore how they may be applied to the specific realm of VR applications. We then discuss the ways in which current practices are insufficient to test VR application interaction and propose a testing architecture for addressing the problems. We present an implementation of the design written on top of the VR Juggler platform. This system allows VR developers to employ standard software engineering techniques that require automated testing methods.
The blue-c Distributed Scene Graph
(The Eurographics Association, 2003) Naef, Martin; Lamboray, Edouard; Staadt, Oliver; Gross, Markus; Andreas Kunz and Joachim Deisinger
In this paper we present a distributed scene graph architecture for use in the blue-c, a novel collaborative immersive virtual environment. We extend the widely used OpenGL Performer toolkit to provide a distributed scene graph maintaining full synchronization down to vertex and texel level. We propose a synchronization scheme including customizable, relaxed locking mechanisms. Our distributed scene graph includes both locally stored nodes for static scene data as well as nodes shared across multiple sites, thus minimizing synchronization overhead. We discuss the performance and demonstrate the functionality of our toolkit with two prototype applications in our high-performance virtual reality and visual simulation environment.
Blue-c: A Spatially Immersive Display and 3D Video Portal
(The Eurographics Association, 2003) Gross, M.; Andreas Kunz and Joachim Deisinger
We present the blue-c, a new generation immersive projection and 3D video acquisition environment for telepresence and collaboration. It combines simultaneous acquisition of multiple life video streams with advanced 3D projection technology in a CAVE<sup>TM</sup>-like environment creating the impression of total immersion. The blue-c portal currently consists of three rectangular projection screens which are built from glass panels containing liquid crystal layers. These screens can be switched from a whitish opaque state to a transparent state allowing the video cameras to "look through the walls". Our projection technology is based on active stereo using two LCD projectors per screen. The projectors are synchronously shuttered along with the screens, the stereo glasses, active illumination devices, and the acquisition hardware. From multiple video streams, we compute a 3D video representation of the user in real-time. The thus created video inlays can be transmitted progressively through networked virtual environments.
CAD/CAE visualization in virtual environment for automotive industry
(The Eurographics Association, 2003) Paillot, D.; Merienne, F.; Thivent, S.; Andreas Kunz and Joachim Deisinger
In this paper we propose a method to link CAD models to an immersive environment. Since CAD models can not be directly viewed in a real-time visualization environment, we present here a complete chain of adapta-tion steps to view adapted CAD models in an immersive environment with high quality rendering. Our method allows high quality visualization of complex scenes in an immersive environment such as design reviewing for example.
Color Consistency for Digital Multi-Projector Stereo Display Systems : The HEyeWall and The Digital CAVE
(The Eurographics Association, 2003) Kresse, W.; Reiners, D.; Knöpfle, C.; Andreas Kunz and Joachim Deisinger
Digital projectors have a significant advantage over CRTs for IPT setups: brightness. But they also have a number of disadvantages, one of which is color consistency. This problem is exacerbated when using the Infitec method for stereo separation, which in itself has some strong advantages for CAVE and tiled wall setups. In this paper we will describe a method for color and brightness correction of multi-projector display systems. The method itself is used in two new projection systems, which are currently under construction at Fraunhofer-IGD: The HEyewall and the Digital CAVE. The HEyeWall is the first stereo capable tiled display worldwide. The Digital CAVE is the first CAVE with digital projectors and stereo separation based on Infitec(tm). In this paper we present these new IPTs in more detail and also present our experience with digital projectors. To calibrate all the involved projectors photometric measurements of the different projectors are used to calculate a common gamut in a linear colorspace. Input colors are mapped into this gamut and from there mapped into the individual projector's colorspace. This method allows to adjust the rendering output of two or more projectors with different color gamuts in such a way that the projected images are photometrically calibrated. Since the correction has to be done for each pixel, a straightforward implementation would be very slow and far away from realtime. Consequently we will outline a method how to improve performance and overcome this limitation.
Color Gamut Matching for Tiled DisplayWalls
(The Eurographics Association, 2003) Wallace, Grant; Chen, Han; Li, Kai; Andreas Kunz and Joachim Deisinger
This paper presents a non-parametric full-gamut color matching algorithm. Color matching is important for the seamless appearance of tiled displays. In particular we address the case where the tiled display is composed of different types of projectors or DLP projectors with white enhancement. White enhancement produces a nonadditive color space that is difficult to model. We perform our calibration using an inexpensive colorimeter as opposed to a highly accurate spectroradiometer. Our results show that we can achieve good color balance with 1.47% variance between projectors. We present a method for applying this color gamut mapping in real-time on the newest commodity graphics cards.
Comparative Visualization of FEM-Based Cutting Simulations in a Virtual Environment
(The Eurographics Association, 2003) Klocke, Fritz; Straube, Andreas M.; Andreas Kunz and Joachim Deisinger
As one of the final steps in the industrial manufacturing chain, machining operations require significant economic consideration. At this stage, design components have already passed through several steps of this value-added manufacturing process. Industrial companies today are using Finite Element Simulations to optimize manufacturing processes, such as mechanical cutting. In order to obtain an increased understanding of the cutting process, several simulations with different input parameters are performed. A new method for comparing these results has been developed and has many potential benefits. In this poster abstract, the comparative visualization of cutting chip formation and distribution of data values, such as tool and work piece temperatures, is investigated using a Virtual Environment.
A Comprehensive Calibration and Registration Procedure for the Visual HapticWorkbench
(The Eurographics Association, 2003) Ikits, Milan; Hansen, Charles D.; Johnson, Christopher R.; Andreas Kunz and Joachim Deisinger
We present a simple yet efficient calibration and registration procedure for improving the overall static display accuracy of the Visual Haptic Workbench. The procedure is used for precisely colocating the visual and haptic workspaces of the system and is divided into three stages. First, we calibrate and register the PHANToM to the display surface of the workbench. Second, we calibrate the tracking system by attaching a rigid extension between the tracker sensor and the PHANToM stylus. Third, we interactively find the remaining unknown display parameters including eye and hotspot offsets as well as a local reference frame. Initial evaluation of the approach indicates that it is possible to improve static display accuracy by at least an order of magnitude for this system.
Detecting Dynamic Occlusion in front of Static Backgrounds for AR Scenes
(The Eurographics Association, 2003) Fischer, Jan; Regenbrecht, Holger; Baratoff, Gregory; Andreas Kunz and Joachim Deisinger
Correctly finding and handling occlusion between virtual and real objects in an Augmented Reality scene is essential for achieving visual realism. Here, we present an approach for detecting occlusion of virtual parts of the scene by natural occluders. Our algorithm is based on a graphical model of static backgrounds in the natural surroundings, which has to be acquired beforehand. The design of the approach aims at providing real-time performance and an easy integration into existing AR systems. No assumptions about the shape or color of occluding objects are required. The algorithm has been tested with several graphical models.
Double Exponential Smoothing: An Alternative to Kalman Filter-Based Predictive Tracking
(The Eurographics Association, 2003) Jr., Joseph J. LaViola; Andreas Kunz and Joachim Deisinger
We present novel algorithms for predictive tracking of user position and orientation based on double exponential smoothing. These algorithms, when compared against Kalman and extended Kalman filter-based predictors with derivative free measurement models, run approximately 135 times faster with equivalent prediction performance and simpler implementations. This paper describes these algorithms in detail along with the Kalman and extended Kalman Filter predictors tested against. In addition, we describe the details of a predictor experiment and present empirical results supporting the validity of our claims that these predictors are faster, easier to implement, and perform equivalently to the Kalman and extended Kalman filtering predictors.
Extending the Working Volume of Projection-based Mixed Reality Systems
(The Eurographics Association, 2003) Splechtna, R.C.; Fuhrmann, A.L.; Andreas Kunz and Joachim Deisinger
The working volume of a Mixed Reality (MR) system - which superimposes the real environment with computer- generated virtual content - strongly depends upon the output/display device used. Single screen projection systems like the Barco Baron Table or the FakeSpace ImmersaDesk M seem rather limited regarding their working volume when compared with the CAVE, which is the only projection-based MR installation providing a wide range of viewing directions. We show how the working volume of such projection based MR systems can be extended by tracking not only the user, but also the projection screen and demonstrate how the tilting mechanism of a standard Barco Baron Table can be used to enlarge the range of usable viewing directions of the system. We also give a description of the complete calibration procedure and set-up necessary to employ this concept with any movable back projection system.
Fast Approximate Visible Set Determination for Point Sample Clouds
(The Eurographics Association, 2003) Mantler, Stephan; Fuhrmann, Anton L.; Andreas Kunz and Joachim Deisinger
We present a fast, efficient method to determine approximate visible sets for vegetation rendered as point sample clouds. A hardware accelerated preprocessing step is used to determine exact visibility for a selected set of views; at runtime the current view is rendered using an approximate visible set constructed from the three closest precalculated views. We will further demonstrate how this method leads to a significant per-frame reduction of the original data size.
Gearbox Widget for Fine Adjustments by Hand Motion
(The Eurographics Association, 2003) OSAWA, Noritaka; REN, Xiangshi; Andreas Kunz and Joachim Deisinger
manipulation by hand is not suitable for making fine adjustments to virtual objects in an immersive environment because it is difficult to hold an unsupported hand in midair and then to release an object at a fixed point. Therefore we propose a virtual 3D gearbox widget. This gearbox widget enables the user to adjust a value precisely. A combination technique of this widget and hand manipulation can move virtual objects and place them in a target position quickly and precisely. For a comparison, we tested the usability of four techniques. Experiments showed that using the proposed gearbox in combination with direct manipulation was the best of the four techniques in terms of both performance data and subjective preference.
Haptic Rendering of Complex Force Fields
(The Eurographics Association, 2003) Krenek, Ales; Andreas Kunz and Joachim Deisinger
With a particular focus in scientific applications, we propose a method of haptic rendering of virtual environments which require rather complex calculations to evaluate their behaviour. Therefore it is not possible to perform the calculations within a haptic loop. We specify a class of problems for which the method is applicable, describe the designed data structure, present involved algorithms, and prove their critical properties. The general section is followed by a case study of applying the method in a specific application in computational chemistry. The paper is concluded with first practical results of deployment of the method as well as preliminary quantitative assessment.

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