STARs

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https://diglib.eg.org/handle/10.2312/232

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Browsing STARs by Title

Now showing 1 - 5 of 5
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    Feature Extraction and Visualisation of Flow Fields
    (Eurographics Association, 2002) Post, Frits H.; Vrolijk, Benjamin; Hauser, Helwig; Laramee, Robert S.; Doleisch, Helmut
    Flow visualisation has already been a very attractive part of visualisation research for a long time. Usually very large data sets need to be processed, which often consist of multivariate data with a large number of sample locations, often arranged in multiple time steps. Recently, the steadily increasing performance of computers again has become a driving factor for a new boom in flow visualisation, especially in techniques based on feature extraction, vector field clustering, and topology extraction. In this state-of-the-art report, an attempt was made to (1) provide a useful categorisation of FlowVis solutions, (2) give an overview of existing solutions, and (3) focus on recent work, especially in the field of feature extraction. In separate sections we describe (a) direct visualisation techniques such as hedgehog plots, (b) visualisation using integral objects, such as streamlines, (c) texture-based techniques, including spot noise and line integral convolution, and (d) techniques based on extraction of features or flow topology.
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    Global Illumination for Interactive Applications and High-Quality Animations
    (Eurographics Association, 2002) Damez, Cyrille; Dmitriev, Kirill; Myszkowski, Karol
    One of the main obstacles to the use of global illumination in image synthesis industry is the considerable amount of time needed to compute the lighting for a single image. Until now, this computational cost has prevented its widespread use in interactive design applications as well as in computer animations. Several algorithms have been proposed to address these issues. In this report, we present a much needed survey and classification of the most up-to-date of these methods. Roughly, two families of algorithms can be distinguished. The first one aims at providing interactive feedback for lighting design applications. The second one gives higher priority to the quality of results, and therefore relies on offline computations. Recently, impressive advances have been made in both categories. Indeed, with the steady progress of computing resources and graphics hardware, and the current trend of new algorithms for animated scenes, common use of global illumination seems closer than ever.
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    Interactive High-Quality Volume Rendering with Flexible Consumer Graphics Hardware
    (Eurographics Association, 2002) Engel, Klaus; Ertl, Thomas
    Recently, the classic rendering pipeline in 3D graphics hardware has become flexible by means of programmable geometry engines and rasterization units. This development is primarily driven by the mass market of computer games and entertainment software, whose demand for new special effects and more realistic 3D environments induced a reconsideration of the once static rendering pipeline. Besides the impact on visual scene complexity in computer games, these advances in flexibility provide an enormous potential for new volume rendering algorithms. Thereby, they make yet unseen quality as well as improved performance for scientific visualization possible and allow to visualize hidden features contained within volumetric data. The goal of this report is to deliver insight into the new possibilities that programmable state-of-the-art graphics hardware offers to the field of interactive, high-quality volume rendering. We cover different slicing approaches for texture-based volume rendering, non-polygonal iso-surfaces, dot-product shading, environment-map shading, shadows, pre- and post-classification, multi-dimensional classification, high-quality filtering, pre-integrated classification and pre-integrated volume rendering, large volume visualization and volumetric effects.
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    Tone Reproduction and Physically Based Spectral Rendering
    (Eurographics Association, 2002) Devlin, Kate; Chalmers, Alan; Wilkie, Alexander; Purgathofer, Werner
    The ultimate aim of realistic graphics is the creation of images that provoke the same responses that a viewer would have to a real scene. This STAR addresses two related key problem areas in this effort which are located at opposite ends of the rendering pipeline, namely the data structures used to describe light during the actual rendering process, and the issue of displaying such radiant intensities in a meaningful way. The interest in the first of these subproblems stems from the fact that it is common industry practice to use RGB colour values to describe light intensity and surface reflectancy. While viable in the context of methods that do not strive to achieve true realism, this approach has to be replaced by more physically accurate techniques if a prediction of nature is intended. The second subproblem is that while research into ways of rendering images provides us with better and faster methods, we do not necessarily see their full effect due to limitations of the display hardware. The low dynamic range of a standard computer monitor requires some form of mapping to produce images that are perceptually accurate. Tone reproduction operators attempt to replicate the effect of real-world luminance intensities. This STAR report will review the work to date on spectral rendering and tone reproduction techniques. It will include an investigation into the need for spectral imagery synthesis methods and accurate tone reproduction, and a discussion of major approaches to physically correct rendering and key tone mapping algorithms. The future of both spectral rendering and tone reproduction techniques will be considered, together with the implications of advances in display hardware.
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    Visual Data Mining
    (Eurographics Association, 2002) Keim, Daniel A.; Müller, Wolfgang; Schumann, Heidrun
    Never before in history has data been generated at such high volumes as it is today. Exploring and analyzing the vast volumes of data has become increasingly difficult. Information visualization and visual data mining can help to deal with the flood of information. The advantage of visual data exploration is that the user is directly involved in the data mining process. There are a large number of information visualization techniques that have been developed over the last two decades to support the exploration of large data sets. In this star report, we provide an overview of information visualization and visual data mining techniques, and illustrate them using a few examples.