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Now showing 1 - 10 of 37
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    HOPI: A Novel High Order Parametric Interpolation in 2D
    (The Eurographics Association, 2006) Xu, Jia; Huang, Zhiyong; Dieter Fellner and Charles Hansen
    This paper presents a novel smooth and convergent high order parametric interpolation method called HOPI with a formal treatment. It employs high order derivatives information and provides more freedom on control of curves. It can be applied to shape design and analysis using curves. This paper reports the work in 2D.
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    Fast and Realistic Display of Clouds Using a Recording Matrix
    (The Eurographics Association, 2006) Wu, Y.; Allgöwer, B.; Nüesch, D.; Dieter Fellner and Charles Hansen
    For volumetric cloud models, traditional ray tracing methods and graphics hardware acceleration methods can result in photorealistic images, but with considerably expensive costs. Hence, real-time rendering can be achieved only under the condition of a static relationship between light sources and clouds. This paper presents a new method to accelerate the rendering process for animated clouds. In order to display visually convincing self-shading properties of clouds, multiple scattering among their internal particles is taken into account with the help of a recording matrix, which only requires small intermediate saving space. This method is not only flexible and easy to use, but also capable of rendering other dynamic gaseous phenomena such as smoke in a fast and efficient manner.
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    Solving Local Reflections: a Direct Methodology
    (The Eurographics Association, 2006) Jeremias, P.; Chavarria, O.; Garcia, O.; Carrillo, X.; Cuñado, A.; Dieter Fellner and Charles Hansen
    Reflection and refraction are key processes intended for realism within simulation platforms. There are several parameters related to those techniques whose values have been traditionally selected by using subjective criteria. This paper presents an interactive water rendering model where the adjustment of the local perturbation parameters has been revised, ensuring physical correctness. Therefore we present new tuning paradigms, based on physical, optical and, besides that, objective constraints.
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    Lighting-Up Geometry: Accurate 3D Modelling of Museum Artifacts with a Torch and a Camera
    (The Eurographics Association, 2006) Vogiatzis, G.; Hernández, C.; Cipolla, R.; Dieter Fellner and Charles Hansen
    This paper addresses the problem of obtaining complete, very detailed reconstructions of shiny objects such as glazed ceramics. We present an algorithm which uses silhouettes of the object, as well as images obtained under changing illumination conditions. In contrast with previous photometric stereo techniques, ours is not limited to a single viewpoint but produces accurate reconstructions in full 3D. A number of images of the object are obtained from multiple viewpoints, under varying lighting conditions. Starting from the silhouettes, the algorithm recovers camera motion and constructs the object s visual hull. This is then used to recover the illumination and initialise a multi-view photometric stereo scheme to obtain a closed surface reconstruction. The algorithm has been implemented as a practical model acquisition system. Here, we present a number of complete reconstructions of challenging real objects.
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    GPU-Based Hierarchical Texture Decompression
    (The Eurographics Association, 2006) Stachera, J.; Rokita, P.; Dieter Fellner and Charles Hansen
    We propose a hierarchical texture compression algorithm for real-time decompression on the GPU. Our algorithm is characterized by low computational complexity, random access and hierarchical structure which allow us to access first three levels of encoded mip-map pyramid. The hierarchical texture compression algorithm HiTCg is based on block-wise approach, where each block is subject to local fractal transform.
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    Fast Skeletal Animation by skinned Arc-Spline based Deformation
    (The Eurographics Association, 2006) Forstmann, Sven; Ohya, Jun; Dieter Fellner and Charles Hansen
    Presented is a novel skeletal animation system for providing high quality geometric deformations in real-time. Each bone of the skeleton is therefore represented by a spline, rather than using conventional matrix rotation. In our approach, each vertex of the animated character can be influenced by a maximum of three spline-curves, which is sufficient for skinned animation. One spline is parameterized by three control points and a possible twist. As opposed to conventional Bézier curves does our arc-spline rely on trigonometric functions for providing better curvatures. The optimized implementation using the OpenGL-shading language shows very promising results for real-time character animation, as even about 1 Million vertices were able to be transformed at interactive 43 frames per second on a GeForce 7800 GTX graphics card.
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    Clothing the Masses: Real-Time Clothed Crowds With Variation
    (The Eurographics Association, 2006) Dobbyn, S.; McDonnell, R.; Kavan, L.; Collins, S.; O'Sullivan, C.; Dieter Fellner and Charles Hansen
    The animation and rendering of crowds of realistically clothed characters presents a difficult challenge in computer graphics, which is further exacerbated when real-time frame rates are required. To date, due to real-time constraints, standard skinning methods have been used to animate the clothes of individuals in real-time crowds, which does not create the appropriate secondary motion for flowing garments. However, plausible cloth simulation is vital for the depiction of realistic characters, so we have developed a novel crowd system in which the individuals are endowed with realism and variety through the addition of physically simulated clothing and hardware assisted pattern variation.
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    Competitive Runtime Performance for Inverse Kinematics Algorithms using Conformal Geometric Algebra
    (The Eurographics Association, 2006) Hildenbrand, Dietmar; Fontijne, Daniel; Wang, Yusheng; Alexa, Marc; Dorst, Leo; Dieter Fellner and Charles Hansen
    Conformal geometric algebra is a powerful tool to find geometrically intuitive solutions. We present an approach for the combination of compact and elegant algorithms with the generation of very efficient code based on two different optimization approaches with different advantages, one is based on Maple, the other one is based on the code generator Gaigen 2. With these results, we are convinced that conformal geometric algebra will be able to become fruitful in a great variety of applications in Computer Graphics.
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    Enhanced Cartoon and Comic Rendering
    (The Eurographics Association, 2006) Spindler, Martin; Röber, Niklas; Döhring, Robert; Masuch, Maic; Dieter Fellner and Charles Hansen
    In this work we present an extension to common cel shading techniques, and describe four new cartoon-like rendering styles applicable for real-time implementations: stylistic shadows, double contour lines, soft cel shading, and pseudo edges. Our work was mainly motivated by the rich set of stylistic elements and expressional possibilities within the medium comic. In particular, we were inspired by Miller s Sin City and McFarlane s Spawn . We designed algorithms for these styles, developed a real-time implementation and integrated it into a regular 3D game engine.
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    Modeling Real-time Rendering
    (The Eurographics Association, 2006) Wong, Chee-Kien Gabriyel; Wang, Jianliang; Dieter Fellner and Charles Hansen
    The real-time rendering process is well known to be extremely dynamic and complex. This paper presents a novel approach to modeling this process via the system identification methodology. Given the process s dynamic nature arising from the possible myriad variations of render states, polygon streams and the non-linearities involved, we describe a modeling approach using neural networks with supervised training from application-generated data. By comparing the outputs of the neural network model s representation of the rendering process with actual empirical data, we discuss the accuracy of our approach in relation to the practical issues of integrating this study to real-world applications.