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Item Poisson-Based Weight Reduction of Animated Meshes(The Eurographics Association and Blackwell Publishing Ltd, 2010) Landreneau, Eric; Schaefer, ScottWhile animation using barycentric coordinates or other automatic weight assignment methods has become a popular method for shape deformation, the global nature of the weights limits their use for real-time applications. We present a method that reduces the number of control points influencing a vertex to a user-specified number such that the deformations created by the reduced weight set resemble that of the original deformation. To do so we show how to set up a Poisson minimization problem to solve for a reduced weight set and illustrate its advantages over other weight reduction methods. Not only does weight reduction lower the amount of storage space necessary to deform these models but also allows GPU acceleration of the resulting deformations. Our experiments show that we can achieve a factor of 100 increase in speed over CPU deformations using the full weight set, which makes real-time deformations of large models possible.Item BqR-Tree: A Data Structure for Flights and Walkthroughs in Urban Scenes with Mobile Elements(The Eurographics Association and Blackwell Publishing Ltd, 2010) Pina, J.L.; Seron, F.; Cerezo, E.Item Optical Image Processing Using Light Modulation Displays(The Eurographics Association and Blackwell Publishing Ltd, 2010) Wetzstein, Gordon; Heidrich, Wolfgang; Luebke, DavidWe propose to enhance the capabilities of the human visual system by performing optical image processing directly on an observed scene. Unlike previous work which additively superimposes imagery on a scene, or completely replaces scene imagery with a manipulated version, we perform all manipulation through the use of a light modulation display to spatially filter incoming light. We demonstrate a number of perceptually motivated algorithms including contrast enhancement and reduction, object highlighting for preattentive emphasis, colour saturation, de-saturation and de-metamerization, as well as visual enhancement for the colour blind. A camera observing the scene guides the algorithms for on-the-fly processing, enabling dynamic application scenarios such as monocular scopes, eyeglasses and windshields.Item New EUROGRAPHICS Fellows(The Eurographics Association and Blackwell Publishing Ltd, 2010)Item Guest Editorial(The Eurographics Association and Blackwell Publishing Ltd, 2010) Joan-Arinyo, Robert; Pereira, Joao MadeirasItem Binary Shading Using Appearance and Geometry(The Eurographics Association and Blackwell Publishing Ltd, 2010) Buchholz, Bert; Boubekeur, Tamy; DeCarlo, Doug; Alexa, MarcIn the style of binary shading, shape and illumination are depicted using two colours, typically black and white, which form coherent lines and regions in the image. We formulate the problem of assigning colours in the rendered image as an energy minimization, computed using graph cut on the image grid. The terms of this energy come from two sources: appearance (shading) and geometry (depth and curvature). Our contributions are in the use of geometric information in determining colours, and how this information is incorporated into a graph cut approach. This optimization yields boundaries between black and white regions that tend towards being shorter and to run along geometric features like creases. We show a range of results, and demonstrate that this approach produces more coherent images than simpler approaches that make local decisions when assigning colours, or that do not use geometry.Item Application of Visual Analytics for Thermal State Management in Large Data Centres(The Eurographics Association and Blackwell Publishing Ltd, 2010) Hao, M. C.; Sharma, R. K.; Keim, D. A.; Dayal, U.; Patel, C.; Vennelakanti, R.Today s large data centres are the computational hubs of the next generation of IT services. With the advent of dynamic smart cooling and rack level sensing, the need for visual data exploration is growing. If administrators know the rack level thermal state changes and catch problems in real time, energy consumption can be greatly reduced. In this paper, we apply a cell-based spatio-temporal overall view with high-resolution time series to simultaneously analyze complex thermal state changes over time across hundreds of racks. We employ cell-based visualization techniques for trouble shooting and abnormal state detection. These techniques are based on the detection of sensor temperature relations and events to help identify the root causes of problems. In order to optimize the data centre cooling system performance, we derive new non-overlapped scatter plots to visualize the correlations between the temperatures and chiller utilization. All these techniques have been used successfully to monitor various time-critical thermal states in real-world large-scale production data centres and to derive cooling policies. We are starting to embed these visualization techniques into a handheld device to add mobile monitoring capability.Item Hierarchical Structure Recovery of Point-Sampled Surfaces(The Eurographics Association and Blackwell Publishing Ltd, 2010) Attene, Marco; Patane, GiuseppeWe focus on the class of regular models defined by Varady et al. for reverse engineering purposes. Given a 3D surface represented through a dense set of points, we present a novel algorithm that converts to a hierarchical representation . In , the surface is encoded through patches of various shape and size, which form a hierarchical atlas. If belongs to the class of regular models, then captures the most significant features of at all the levels of detail. In this case, we show that can be exploited to interactively select regions of interest on and intuitively re-design the model. Furthermore, intrinsically encodes a hierarchy of useful segmentations of . We present a simple though efficient approach to extract and optimize such segmentations, and we show how they can be used to approximate the input point sets through idealized manifold meshes.Item Computational Aesthetics 2010 in London, England, June 14-15, 2010, sponsored by Eurographics, in collaboration with ACM SIGGRAPH(The Eurographics Association and Blackwell Publishing Ltd, 2010) Isenberg, Tobias; Dodgson, NeilItem Resampling Strategies for Deforming MLS Surfaces(The Eurographics Association and Blackwell Publishing Ltd, 2010) Gois, Joao Paulo; Buscaglia, Gustavo C.Moving-least-squares (MLS) surfaces undergoing large deformations need periodic regeneration of the point set (point-set resampling) so as to keep the point-set density quasi-uniform. Previous work by the authors dealt with algebraic MLS surfaces, and proposed a resampling strategy based on defining the new points at the intersections of the MLS surface with a suitable set of rays. That strategy has very low memory requirements and is easy to parallelize. In this article new resampling strategies with reduced CPU-time cost are explored. The basic idea is to choose as set of rays the lines of a regular, Cartesian grid, and to fully exploit this grid: as data structure for search queries, as spatial structure for traversing the surface in a continuation-like algorithm, and also as approximation grid for an interpolated version of the MLS surface. It is shown that in this way a very simple and compact resampling technique is obtained, which cuts the resampling cost by half with affordable memory requirements.