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Now showing 1 - 4 of 4
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    A Breadth-First Approach To Efficient Mesh Traversal
    (The Eurographics Association, 1998) Mitra, Tulika; Chiueh, Tzi-cker; S. N. Spencer
    Complex 3D polygonal models are typically represented as triangular meshes, especially when they are generated procedurally, or created from volumetric data sets through surface extraction. Existing 3D rendering hardware, on the other hand, processes one triangle at a time. Therefore triangle meshes need to be converted to individual triangles when they are fed to the graphics pipeline. The design goal of such conversion algorithms is to minimize the number of vertices that are sent redundantly to the rendering pipeline. This paper proposes a breadth-first approach to traverse triangle meshes that reduces vertex redundancy to very close to the theoretical minimum. With the proposed scheme, no triangle vertices need to be specified multiple times, barring exceptional cases. In addition, owing to a prefetching technique, the on-chip storage requirement for effective mesh traversal remains small and largely constant regardless of the mesh size. Our experimental results show that assuming a 64-vertex buffer, the redundant transformation overhead associated with the proposed approach is between 1.00% and 7.33%, for a set of 8 triangle meshes whose size ranges from 2,992 to 40,000 triangles.
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    Heresy: A Virtual Image-Space 3D Rasterization Architecture
    (The Eurographics Association, 1997) Chiueh, Tzi-cker; A. Kaufmann and W. Strasser and S. Molnar and B.-O. Schneider
    With the advent of virtual reality and other visual applications that require photo and cinema realism, 3D graphics hardware has started to enter into the main stream. This paper describes the design and evaluation of a cost-effective highperformance 3D graphics system called Heresy that is based on virtual image-space architecture. Heresy features three novel architectural mechanisms. First, the lazy shading mechanism renders the shading computation effort to be proportional to the screen area but independent of the scene complexity. Second, the speculative Z-buffer hardware allows one-cycle Z-value comparison, as opposed to four cycles in conventional designs. Third, to avoid the intermediate sorting required by virtual image-space rasterization architecture, we develop an innovative display database traversal algorithm that is tailored to given user projection views. With this technique, the sorting-induced delay and extra memory requirements associated with image-order rasterization are completely eliminated. By replicating the Heresypipeline, it is estimated that the overall performance of the system can reach over 1 million Gouraud-shaded and 2D mip-mapped triangles per second at 20 frames/set with 1K x 1K resolution per frame.
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    I/O-Conscious Volume Rendering
    (The Eurographics Association, 2001) Yang, Chuan-Kai; Chiueh, Tzi-cker; David S. Ebert and Jean M. Favre and Ronald Peikert
    Most existing volume rendering algorithms assume that data sets are memory-resident and thus ignore the performance overhead of disk I/O. While this assumption may be true for high-performance graphics machines, it does not hold for most desktop personal workstations. To minimize the end-to-end volume rendering time, this work re-examines implementation strategies of the ray casting algorithm, taking into account both computation and I/O overheads. Specifically, we developed a data-driven execution model for ray casting that achieves the maximum overlap between rendering computation and disk I/O. Together with other performance optimizations, on a 300-MHz Pentium-II machine, without directional shading, our implementation is able to render a 128x128 greyscale image from a 128x128x128 data set with an average end-to-end delay of 1 second, which is very close to the memory-resident rendering time. With a little modification, this work can also be extended to do out-of-core visualization as well.
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    Characterization of Static 3D Graphics Workloads
    (The Eurographics Association, 1997) Chiueh, Tzi-cker; Lin, Wei-jen; A. Kaufmann and W. Strasser and S. Molnar and B.-O. Schneider
    3D graphics transform 3D models into 2D images by simulating the physics of light propagation from the lighting sources, through the objects, and eventually to the eyes. Although specialized graphics hardware engines have been proposed and implemented in the past, and a heated interest in PC-class 3D graphics cards is currently emerging, detailed descriptions and analysis of 3D graphics workloads which graphics hardware design can be based on are almost non-existent. This work takes the first step towards a comprehensive 3D graphics workload characterization by reporting the results of an empirical study using an instrumented software polygonal renderer tested on a wide variety of static 3D graphics models with sufficiently sophisticated geometric and texture properties.