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Now showing 1 - 3 of 3
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    Leaf Cluster Impostors for Tree Rendering with Parallax
    (The Eurographics Association, 2005) Garcia, Ismael; Sbert, Mateu; Szirmay-Kalos, László; John Dingliana and Fabio Ganovelli
    This paper presents a simple method to render complex trees on high frame rates while maintaining parallax effects. Based on the recognition that a planar impostor is accurate if the represented polygon is in its plane, we find an impostor for each of those groups of tree leaves that lie approximately in the same plane. The groups are built automatically by a clustering algorithm. Unlike billboards, these impostors are not rotated when the camera moves, thus the expected parallax effects are provided. On the other hand, clustering allows the replacement of a large number of leaves by a single semi-transparent quadrilateral, which improves rendering time considerably. Our impostors well represent the tree from any direction and provide accurate depth values, thus the method is also good for shadow computation.
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    Real-Time Rendering of Cloudy Natural Phenomena with Hierarchical Depth Impostors
    (The Eurographics Association, 2005) Ummenhoffer, Tamás; Szirmay-Kalos, László; John Dingliana and Fabio Ganovelli
    This paper presents a real-time method to realistically render dynamic participating media under changing lighting conditions. In order to cope with performance requirements, the volume is built of instances of particle blocks. The simulation and rendering happen on two levels, on the block level and on the volume level. On the volume level blocks are replaced by depth impostors, which allows for very fast recalculation of the cloud illumination. Including depth information into block impostors our technique also eliminates billboard clipping artifacts when the participating medium contains objects. The proposed method can render swirling clouds and smoke on high frame rates, and can be used in real-time applications.
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    Photon Map Gathering on the GPU
    (The Eurographics Association, 2005) Czuczor, Szabolcs; Szirmay-Kalos, László; Szécsi, László; Neumann, László; John Dingliana and Fabio Ganovelli
    Photon mapping methods obtain the indirect illumination of a point by finding those photon hits that arrived at the neighborhood of the point on the object surface. This paper proposes a method that stores the photon hits in a texture of the graphics hardware and replaces the traditional kd-tree based neighborhood searches by the filtering of this texture. This step finds the irradiance of all points (i.e. all texels) simultaneously in a single step, thus the average irradiance of a point can be obtained by a single texture lookup. Using this approach we can port the final gathering step of photon mapping to the graphics hardware (GPU). The CPU is only responsible for generating new light paths and updating the unfiltered photon map. Thanks to the optimal subdivision of the computation work between the the CPU and the GPU, the proposed algorithm can render globally illuminated scenes interactively.