EG1999
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Item Virtual Reconstruction of Medieval Architecture(Eurographics Association, 1999) Masuch, M.; Freudenberg, B.; Ludowici, B.; Kreiker, S.; Strothotte, T.We describe the reconstruction of a medieval building as an example of how the use of 3D computer graphics can facilitate the reconstruction of an ancient site. We suggest that different stages of a virtual reconstruction imply the use of different rendering techniques, as the style of visualization has a significant impact on both the reconstruction process and the presentation to non-expert viewers.Item 3D laser scanning numerical surface definition and fast prototyping of the Basel Bronze Head(Eurographics Association, 1999) Accardo, Giorgio; Scarpetta, MassimilianoStarting from the experiences and results deriving from the cooperation between the Istituto Centrale del Restauro, Fox Bit srl and certain academic institutions, a study is presented which is aimed at using and adapting reverse engineering (RE) and fast prototyping (FR) industrial techniques to cultural property conservation.Item A Study of Automatic Program Production Using TVML(Eurographics Association, 1999) Douke, Mamoru; Makino, Eiji; Hayashi, MasakiThis paper describes a method to create TV programs automatically using TVML(TV program Making Language). TVML is a scripting language that we have developed for generating TV programs by computer. In this paper, we focus on automatic news program creation. We define XML tags for describing contents of a news program, and presentation data for creating the program by given XML file. We have also developed an automatic news program creation software based on the idea.Item Tutorial 2 - Level-of-Detail in Surface and Volume Modeling(Eurographics Association, 1999) De Floriani, Leila; Puppo, Enrico; Cignoni, Paolo; Scopigno, Roberto-Item Schock in the ear: sound and new media art(Eurographics Association, 1999) Neumark, NorieNew media art generally fails to engage with the imaginative and artistic possibilities and particularities of sound. Shock in the Ear is a sound -centred experimental art CDROM which explores shock -- from culture shock to electric shock and reverberating beyond into shock aesthetics.Item Perceptual Principles and Computer Graphics(Eurographics Association, 1999) May, J.Until comparatively recently, the major problems in computer display technology were caused by the difficulty of making anything recognisable at all. Eighty character-width displays, with eight or nine brilliant green lines per character, slow to respond and slow to decay, somehow enabled people to use their vast new computers with their kilobytes of memory. The pace of change should really astonish us, as we contemplate flat, bright and crisp LCD screens that require separate graphics processors and megabytes of video memory chips just to display our favourite desktop images. It now seems possible for our technological artefacts to display almost anything in as much detail as we would like, whether from a high resolution photographic image or, via skilfully implemented algorithms, by photorealistic rendering from data. In the course of this rapid development, the major problems have themselves changed: now we must ask ourselves what it means for our displays to be recognisable, and what is it in the display that needs to be recognised?Item The Norwich Virtual City Project(Eurographics Association, 1999) Arnold, D. B.; Day, A. M.This paper describes the early work on implementing a visitor attraction based on the heritage of the Norwich area. The project has been in planning for about three years, but has only just been funded and is due to open in 2001. The paper reviews the background to the project and the city, and considers the expected benefits of the venture. The range of data sources are then reviewed and areas are highlighted where computer science research needs to progress to maximise benefits. The paper then reviews progress to date on the project.Item Fast Distance Field Interpolation for Reconstruction of Surfaces from Contours(Eurographics Association, 1999) Klein, Reinhard; Schilling, AndreasOne simple and robust way to get a reconstruction of surfaces from a given contour stack dealing well with branching and other problems which are generally difficult to solve is based on the well known MC-algorithm. To overcome the staircase artefacts produced by the MC-algorithm Jones et. al. 3 proposed to use a distance field interpolation between the slices and to run the MC-algorithm on this distance field. The main problem of this approach is the distance field computation as it is very time consuming especially if high resolution grids (e.g. 10241024 are used. Therefore, in the original algorithm the resolution of the chosen grid is much less than the resolution of the given contour sacrificing accuracy of the resulting surface. Especially in medical applications this is not accepted by the doctors. In this paper we introduce a new method for the computation of the discrete distance field, which is a breaktrough in terms of speed and accuracy. This new method allows us to reconstruct surfaces from contour stacks with guaranteed accuracy in reasonable time. Several examples show the power of this approach.Item The Danteum(Eurographics Association, 1999) Nagakura, TakehikoThe Danteum was a building designed for Rome in 1938 by two eminent Italian architects, Giuseppe Terragni and Pietro Lingeri. Due to the defeat of their client, Mussolini, in WW II, the project was never realized and became one of the best known unbuilt modern projects. Through the use of advanced computer graphics technology, an attempt has been made to simulate a walk-through experience of light and materials inside this unbuilt monument. This animated representation revealed two of the important spatial characters embedded in the design of this building: a constant oscillation of dark and light as well as that of closed and open.Item Visible Surface Reconstruction with Accurate Localization of Object Boundaries(Eurographics Association, 1999) March, Riccardo; Pedersini, FedericoAn important problem in 3D reconstruction from multiple perspective views is the accurate recovery of surfaces near the discontinuities (object boundaries and creases). A common limitation of many techniques based on regularization methods is the poor quality of the results near the surface discontinuities. In this paper, we present a reconstruction method that is able to perform the surface recovery with an accurate preservation and localization of the discontinuities. The method is based on an iterative optimization algorithm. Experimental results using both synthetic and real data are presented for proving the effectiveness of the proposed approachItem On Time-Varying Flow Fields: a streakline-based visualization method(Eurographics Association, 1999) Sanna, Andrea; Montrucchio, Bartolomeo; Arina, RenzoThe visualization of unsteady flows is an attractive field of research and texture-based techniques seem to provide satisfactory results. In this paper we propose a texture-based method which follows streaklines in order to produce an effective visualization of time-dependent phenomena. Our approach allows to overcome the lack of temporal coherence due to instantaneous methods which depict each frame of an animation without considering the temporal correlation with the previous time steps.Item A VR based safety training in a petroleum refinery(Eurographics Association, 1999) Haller, Michael; Holm, Roland; Volkert, Jens; Wagner, RolandWe present the prototype omVR, which is a Virtual Reality based safety training system in a petroleum refinery. It provides an advanced technique for personnel safety training and allows users to navigate through the training setup and interact with parts of the refinery. By using a head mounted display a high degree of immersion is achieved. omVR is the implementation of a training scenario, which is too dangerous, difficult, or expensive to be performed in real life. In our system the trainer has the possibility to control the scenario from a remote trainer module which communicates with the VR simulation program.Item 3D Geometry Compressionand Progressive Transmission(Eurographics Association, 1999) Taubin, GabrielPolygonal meshes remain the primary representation for visualization of 3D data in a wide range of industries, including manufacturing, architecture, geographic information systems, medical imaging, robotics, entertainment, and military applications. Because of its widespread use, it is desirable to compress polygonal meshes stored in file servers and exchanged over computer networks to reduce storage and transmission time requirements. In this report we describe several schemes that have been recently introduced to represent single and multi-resolution polygonal meshes in compressed form, and to progressively transmit polygonal mesh data. The progressive transmission of polygonal meshes allows the decoder process to make part of a single-resolution mesh, or the low resolution levels of detail of a multi-resolution mesh, available to the rendering system before the whole bitstream is fully received and decoded. It is desirable to combine compression and progressive transmission, but not all the existing methods exhibit both features. These progressive transmission schemes are closely related to surface simplification or decimation methods, which change the surface topology while approximating the geometry, and can be regarded as lossy compression schemes as well. Finally, we describe in more detail the Topological Surgery and Progressive Forest Split schemes that are currently part of the MPEG-4 multimedia standard.Item A Global Routing Mechanism for Modular VRML-Worlds(Eurographics Association, 1999) Mader, S.With the increasing complexity of virtual worlds VRML97 reveals its lack of native support for logical modularization of these worlds. Though the inherent mechanisms as PROTO-typing and Inlining allow us to partition our worlds into several files, the restriction to file-limited namespaces makes an event-routing for complex interactions between different modules a rather difficult task. In this paper we present an easy-to-use method for event-based communication across modular VRML scenes. Based on VRML´s event model, this solution goes conform with the VRML97 standard ISO/IEC 14772-1:19971 . In order to show its ability to support the implementation of highly interactive and complex VRML-worlds we demonstrate its application in a current project from the fields of virtual heritage.Item Interactive Information System for the Camposanto Monumentale of Pisa(Eurographics Association, 1999) Baracchini, C.; Brogi, A.; Merlitti, D.Multimedia Database gathering the historical-preservative documentation of the monumental complex, including a digital reconstruction achieved through a solid modelling of the building and its fittings.Item Wavelet Projections for Volume Rendering(Eurographics Association, 1999) Horbelt, Stefan; Unser, Michael; Vetterli, MartinWe extended Gross’s 3 method of volume wavelet rendering by computing splats via an orthogonal projection operator. The method decomposes the volume data into a wavelet pyramid representation in the spline domain. The splats of the basis functions are approximated on a multiresolution grid. Using least-squares approximation ensures the smallest possible error for a given sampling step size. The approximation error on the grid is derived as a function of the sampling step h. The choice of the appropriate wavelet space and spatial resolution at each step produces the smallest possible filters. Our approach reduces the number of computations and allows full control of the image quality.Item Animating Brachiation(Eurographics Association, 1999) Zhang, Zheng; Wong, Kok CheongThis paper presents a physically-based animation system for generating realistic motion of primate brachiation. One of the main aims of this system is to facilitate the process of generating brachiation sequences with appropriate automaticity and also provide the animator with adequate controllability. A hybrid system based on an integration of three control modules of different levels. The low-level control module, namely forward dynamics interactive module can be employed to rapidly manipulate the torque values at specific joints of a simplied primate figure. Both the mid-level and high-level control modules are designated to automate the process of generating the basic global brachiation movements of the primate figure. The performance of the system is evaluated by measuring the animation results qualitatively and quantitatively. Experimental results have demonstrated the effectiveness and robustness of the paradigm by generating animated sequences of realistic brachiating motionItem Registration methods for harmonious integration of real worlds and computer generated objects(Eurographics Association, 1999) Simon, G.; Lepetit, V.; Berger, M.-O.This page is an extension of our paper entitled "Registration methods for harmonious integration of real and computer generated objects". We focus in this paper on the problem of adding computer-generated objects in video sequences. We propose a robust method for viewpoint computation which utilizes 3D knowledge on the scene as well as 2D/2D correspondences of key-points. Next, we extend this method to the case of unknown focal length varying from image to image. Finally, we describe how to solve possible occlusions between the computer generated objects and the real scene. Many videos illustrating these different points are presented here.Item Tutorial 6 - Rendering and Visualization in Parallel Environments(Eurographics Association, 1999) Bartz, Dirk; Schneider, Bengt-Olaf; Silva, ClaudioThe continuing commoditization of the computer market has precipitated a qualitative change. Increasingly powerful processors, large memories, big harddisk, high-speed networks, and fast 3D rendering hardware are now affordable without a large capital outlay. A new class of computers, dubbed Personal Workstations, has joined the traditional technical workstation as a platform for 3D modeling and rendering. In this tutorial, attendees will learn how to understand and leverage both technical and personal workstations as components of parallel rendering systems. The goal of the tutorial is twofold: Attendees will thoroughly understand the important characteristics workstations architectures. We will present an overview of different workstation architectures, with special emphasis on current technical and personal workstations, addressing both single-processors as well as SMP architectures. We will also introduce important methods of programming in parallel environment with special attention how such techniques apply to developing parallel renderers. Attendees will learn about different approaches to implement parallel renderers. The tutorial will cover parallel polygon rendering and parallel volume rendering. We will explain the underlying concepts of workload characterization, workload partitioning, and static, dynamic, and adaptive load balancing. We will then apply these concepts to characterize various parallelization strategies reported in the literature for polygon and volume rendering. We abstract from the actual implementation of these strategies and instead focus on a comparison of their benefits and drawbacks. Case studies will provide additional material to explain the use of these techniques. The tutorial will be structured into two main sections: We will first discuss the fundamentals of parallel programming and parallel machine architectures. Topics include message passing vs. shared memory, thread programming, a review of different SMP architectures, clustering techniques, PC architectures for personal workstations, and graphics hardware architectures. The second section builds on this foundation to describe key concepts and particular algorithms for parallel polygon rendering and parallel volume rendering.Item WebTalk: a 3D collaborative environment to access the Web(Eurographics Association, 1999) Paolini, P.; Barbieri, T.; Loiudice, P.; Alonzo, F.; Arru, M.; Zanti, M.; Gaia, G.The notion of cooperative visit and interaction within a web site, both at 2D and 3D level, could add decisive motivation to pursue exploitation of the third dimension in networked environments. A prototype developed at the HOC laboratory in Politecnico of Milan, WEBTALK, allows development of custom 3D environments in which actions and situations can be shared throughout a network. The current prototype makes use of standard web-based Internet/Intranet technology: it is composed of a VRML (Virtual Reality Modeling Language) graphical engine and a Java-based TCP/IP (the Internet Protocol) communication layer. The technique has proven itself successful and has given rise to several interesting applications, such as the creation of Virtual 3D Museum Spaces at the National Science Museum (www.museoscienza.org), in which visitors can visit the museum interacting with the exhibits themselves and sharing their experiences with other visitors - even joining a guided tour with the virtual museum guide. A new prototype will make use of a completely Java-based environment, using Sun’s Java 2 and Java 3D. The new WEBTALK will stress even further the issues of third party external authoring of virtual worlds and of cooperation patterns within the shared environments, with a distinction between shared object geometries, shared object behaviors, shared object data (stored in an on-line DBMS), and cooperation metaphors within the virtual world. Linking to 2D-based web sites resources will lead cooperation patterns to be extended also to regular web-space.