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Now showing 1 - 5 of 5
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    Interactive Rendering of Atmospheric Scattering Effects Using Graphics Hardware
    (The Eurographics Association, 2002) Dobashi, Yoshinori; Yamamoto, Tsuyoshi; Nishita, Tomoyuki; Thomas Ertl and Wolfgang Heidrich and Michael Doggett
    To create realistic images using computer graphics, an important element to consider is atmospheric scattering, that is, the phenomenon by which light is scattered by small particles in the air. This effect is the cause of the light beams produced by spotlights, shafts of light, foggy scenes, the bluish appearance of the earth s atmosphere, and so on. This paper proposes a fast method for rendering the atmospheric scattering effects based on actual physical phenomena. In the proposed method, look-up tables are prepared to store the intensities of the scattered light, and these are then used as textures. Realistic images are then created at interactive rates by making use of graphics hardware.
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    Adaptive Texture Maps
    (The Eurographics Association, 2002) Kraus, Martin; Ertl, Thomas; Thomas Ertl and Wolfgang Heidrich and Michael Doggett
    We introduce several new variants of hardware-based adaptive texture maps and present applications in two, three, and four dimensions. In particular, we discuss representations of images and volumes with locally adaptive resolution, lossless compression of light fields, and vector quantization of volume data. All corresponding texture decoders were successfully integrated into the programmable texturing pipeline of commercial off-the-shelf graphics hardware.
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    The Ray Engine
    (The Eurographics Association, 2002) Carr, Nathan A.; Hall, Jesse D.; Hart, John C.; Thomas Ertl and Wolfgang Heidrich and Michael Doggett
    Assisted by recent advances in programmable graphics hardware, fast rasterization-based techniques have made significant progress in photorealistic rendering, but still only render a subset of the effects possible with ray tracing. We are closing this gap with the implementation of ray-triangle intersection as a pixel shader on existing hardware. This GPU ray-intersection implementation reconfigures the geometry engine into a ray engine that efficiently intersects caches of rays for a wide variety of host-based rendering tasks, including ray tracing, path tracing, form factor computation, photon mapping, subsurface scattering and general visibility processing.
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    Efficient Rendering of Spatial Bi-directional Reflectance Distribution Functions
    (The Eurographics Association, 2002) McAllister, David K.; Lastra, Anselmo; Heidrich, Wolfgang; Thomas Ertl and Wolfgang Heidrich and Michael Doggett
    We propose texture maps that contain at each texel all the parameters of a Lafortune representation BRDF as a compact, but quite general surface appearance representation. We describe a method for rendering such surfaces rapidly on current graphics hardware and demonstrate the method with real, measured surfaces and hand-painted surfaces. We also propose a method of rendering such spatial bi-directional reflectance distribution functions using prefiltered environment maps. Only one set of maps is required for rendering the different BRDFs stored at each texel over the surface.
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    Low Latency Photon Mapping Using Block Hashing
    (The Eurographics Association, 2002) Ma, Vincent C. H.; McCool, Michael D.; Thomas Ertl and Wolfgang Heidrich and Michael Doggett
    For hardware accelerated rendering, photon mapping is especially useful for simulating caustic lighting effects on non-Lambertian surfaces. However, an efficient hardware algorithm for the computation of the k nearest neighbours to a sample point is required. Existing algorithms are often based on recursive spatial subdivision techniques, such as kd-trees. However, hardware implementation of a tree-based algorithm would have a high latency, or would require a large cache to avoid this latency on average. We present a neighbourhood-preserving hashing algorithm that is low-latency and has sub-linear access time. This algorithm is more amenable to fine-scale parallelism than tree-based recursive spatial subdivision, and maps well onto coherent block-oriented pipelined memory access. These properties make the algorithm suitable for implementation using future programmable fragment shaders with only one stage of dependent texturing.