STARs

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https://diglib.eg.org/handle/10.2312/216

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3D Geometry Compressionand Progressive Transmission
(Eurographics Association, 1999) Taubin, Gabriel
Polygonal 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.
Graph Visualisation and Navigation in Information Visualisation
(Eurographics Association, 1999) Herman, I.; Melancon, G.; Marshall, M.S.
This is a survey on graph visualisation and navigation techniques, as used in information visualisation. Graphs appear in numerous applications, like web browsing, state–transition diagrams, computer data structures, etc. The ability to visualise and to navigate in these potentially very large, abstract graphs is often a crucial part of an application. Information visualisation has specific requirements, which means that this survey approaches the results of traditional graph drawing from a different perspective than the traditional surveys; as such it is a useful complementary survey to those
Graphics, Vision, and Visualization in Medical Imaging: A State of the Art Report
(Eurographics Association, 1999) Ezquerra, Norberto; Navazo, Isabel; Morris, Tahia Infantes; Monclus, Eva
The field of medical imaging has significantly changed over the years, becoming both an integral part of health care and an increasingly important area of research spanning many disciplines. As the title of this paper suggests, one interesting result of this evolutionary process has been the fusion of traditionally disjointed yet highly interrelated areas: from computer vision and image processing, through graphics and visualization, to the integration of creative immersion and robotics-based mechanisms for interactively manipulating the information. As a result of these innovations, medical imaging has continued to re-invent itself, fundamentally changing the ways in which we see, communicate about, learn from, and interact with, medical information. With this in mind, the purpose of this state-of-the-art (STAR) report is two-fold. On one hand, the aim is to provide a brief summary of some of the salient methods, results, and potentially powerful trends that currently describe the field. On the other hand, the goal is to outline some of the remaining challenges as well as the possible opportunities. Clearly, the field is far too broad and complex for a single article to adequately reflect the technical depth and extraordinary diversity of even a small portion of these topics. Thus, without any claim at completeness, the emphasis will be placed on highlighting selected frontier research activities and applications, focussing on aspects related to vision, graphics and visualization from an interpretive (rather than tutorial) perspective. In addition to these discussions, a list of URLs of some of the groups actively engaged in medical imaging research is also included. The overall objective is therefore to provide a "snap shot" of the field through a brief summary that will hopefully serve as a useful source of information for those wanting to learn more about the field, and, for those actively engaged in the field, a timely -and possibly inspirational- reference.
Modelling and Haptic Interaction with non-rigid materials
(Eurographics Association, 1999) Cugini, U.; Bordegoni, M.; Rizzi, C.; De Angelis, F.; Prati, M.
This report presents an overview of main modelling and simulation techniques for non–rigid objects discussing advantages and disadvantages. Related techniques to face several problems rising when dealing with deformable objects simulation are also discussed. They concern numerical solvers, constraints management and collision detection. In the simulation of non-rigid objects another relevant issue is the provision of operational modality at higher and higher level and more and more useroriented. The paradigm of haptic interaction recently developed seems promising to achieve this goal. Haptic interaction allows the users to feel several physical properties of the modelled objects through the manipulation of their virtual representation. Thus, second part of the report focuses on the state-of-theart of haptic devices, technologies and applications concerning interaction with non-rigid models. A classification from different point of views is proposed. The specific work our group is performing in the area of non-rigid objects modelling and simulation and haptic interaction with non-rigid models is also illustrated.
Multiresolution Modeling: Survey and Future Opportunities
(Eurographics Association, 1999) Garland, Michael
For twenty years, it has been clear that many datasets are excessively complex for applications such as real-time display, and that techniques for controlling the level of detail of models are crucial.More recently, there has been considerable interest in techniques for the automatic simplification of highly detailed polygonalmodels into faithful approximations using fewer polygons. Several effective techniques for the automatic simplification of polygonal models have been developed in recent years. This report begins with a survey of the most notable available algorithms. Iterative edge contraction algorithms are of particular interest because they induce a certain hierarchical structure on the surface. An overview of this hierarchical structure is presented,including a formulation relating it to minimum spanning tree construction algorithms. Finally, we will consider the most significant directions in which existing simplification methods can be improved, and a summary of other potential applications for the hierarchies resulting from simplification.
Radiosity for Large Vegetation Scenes
(Eurographics Association, 1999) Mastal, Helmut; Tobler, Robert F.; Purgathofer, Werner
Calculating radiosity solutions for large scenes containing multiple plants is all but impossible using the radiosity method in its original form. With the introduction of sophisticated hierarchical and clustering algorithms radiosity for vegetation scenes becomes a solvable challenge. The precomputation of the diffuse light distribution in leaf canopies of forests and other plants can be used to calculate realistic images, but also for agricultural planning purposes. This state of the art report gives an overview of the methods that can, and have been, used to calculate global illumination in vegetation scenes, including hierarchical methods, statistical methods based on simplifications, and specialized methods that have been optimized to handle scenes with a dense, non-isotropic distribution of objects such as canopies.

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