EGGH02: SIGGRAPH/Eurographics Workshop on Graphics Hardware 2002

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https://diglib.eg.org/handle/10.2312/333

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Browsing EGGH02: SIGGRAPH/Eurographics Workshop on Graphics Hardware 2002 by Subject "Color"

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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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    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.