VMV13

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https://diglib.eg.org/handle/10.2312/1017

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Browsing VMV13 by Subject "Computer Graphics [I.3.3]"

Now showing 1 - 3 of 3
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    Evaluating the Perceptual Impact of Rendering Techniques on Thematic Color Mappings in 3D Virtual Environments
    (The Eurographics Association, 2013) Engel, Juri; Semmo, Amir; Trapp, Matthias; Döllner, Jürgen; Michael Bronstein and Jean Favre and Kai Hormann
    Using colors for thematic mapping is a fundamental approach in visualization, and has become essential for 3D virtual environments to effectively communicate multidimensional, thematic information. Preserving depth cues within these environments to emphasize spatial relations between geospatial features remains an important issue. A variety of rendering techniques have been developed to preserve depth cues in 3D information visualization, including shading, global illumination, and image stylization. However, these techniques alter color values, which may lead to ambiguity in a color mapping and loss of information. Depending on the applied rendering techniques and color mapping, this loss should be reduced while still preserving depth cues when communicating thematic information. This paper presents the results of a quantitative and qualitative user study that evaluates the impact of rendering techniques on information and spatial perception when using visualization of thematic data in 3D virtual environments. We report the results of this study with respect to four perception-related tasks, showing significant differences in error rate and task completion time for different rendering techniques and color mappings.
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    Illustrative Rendering of Particle Systems
    (The Eurographics Association, 2013) Chandler, Jennifer; Obermaier, Harald; Joy, Kenneth I.; Michael Bronstein and Jean Favre and Kai Hormann
    Sets of particles are a frequently used tool for the exploration of time-varying flow fields due to their ease of use and conceptual simplicity. Understanding temporal changes in such particle systems can be difficult with traditional visualization methods such as isosurface rendering and particle splatting. These types of methods only show the current shape of the point cloud and give no context about how the current time step relates to previous or future time steps. In this paper we present an illustrative rendering approach to visualizing particle systems. We use illustrative rendering techniques like silhouettes and trajectory arrows combined with volume raycasting to highlight important features in the particle system and show how these features change across time steps. Our method allows users to easily identify structures within the point cloud and understand how they evolve over time.
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    Parallelized Global Brain Tractography
    (The Eurographics Association, 2013) Philips, Stefan; Hlawitschka, Mario; Scheuermann, Gerik; Michael Bronstein and Jean Favre and Kai Hormann
    Most brain tractography algorithms suffer from lower accuracy, because they use only information in a certain neighborhood and reconstruct the tracts independently. Global brain tractography algorithms compensate the lack of accuracy of those local algorithms in certain areas by optimizing the whole tractogram. The global tractography approach by Reisert et al. showed the best results in the Fiber Cup contest, but the runtime is still a matter for a medical application. In this paper we present the non-trivial parallelization of this global tractography algorithm. The parallelization exploits properties of the algorithm and modifies the algorithm where necessary. We compare the runtimes of the serial and the parallel variant and show that the outcomes of the parallel variant are of the same quality as those of the serial algorithm. The experiments proof also that the parallelization scales well for real world datasets.