Browsing by Subject "Radiosity"

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    Parallel processing for progressive refinement radiosity
    (1993) Çapın, Tolga K.
    Progressive refinement radiosity is an increasingly popular method for realistic image synthesis of non-existing environments. The method successfully approximates the light distribution in an environment, however it requires excessive amount of computation. In this thesis, the progressive refinement method is investigated for parallelization on ring and hypercube-connected multicomputers. Two different approaches for parallelization, based on synchronous parallelism witli static task assignment, are proposed, in order to achieve better coherence in parallel light distributions and obtain good performance on simple topologies. Efficient global circulation schemes are proposed in order to decrease the total volume of communication by asymptotical factors. The first scheme for parallelization is a modification of the sequential algorithm in that several patches shoot their energy at a time, while the second scheme is based on the parallelism level of one shooting patch at a time. The proposed parallel algorithms are evaluated theoretically and implemented for ring and hypercube-connected topologies on Intel’s iPSC72 multicomputer. Load balance quality of the proposed schemes are evaluated experimentally
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    A parallel progressive radiosity algorithm based on patch data circulation
    (Pergamon Press, 1996) Aykanat, Cevdet; Çapin, T. K.; Özgüç, B.
    Abstract - Current research on radiosity has concentrated on increasing the accuracy and the speed of the solution. Although algorithmic and meshing techniques decrease the execution time, still excessive computational power is required for complex scenes. Hence, parallelism can be exploited for speeding up the method further. This paper aims at providing a thorough examination of parallelism in the basic progressive refinement radiosity, and investigates its parallelization on distributed-memory parallel architectures. A synchronous scheme, based on static task assignment, is proposed to achieve better coherence for shooting patch selections. An efficient global circulation scheme is proposed for the parallel light distribution computations, which reduces the total volume of concurrent communication by an asymptotical factor. The proposed parallel algorithm is implemented on an Intel's iPSC/2 hypercube multicomputer. Load balance qualities of the proposed static assignment schemes are evaluated experimentally. The effect of coherence in the parallel light distribution computations on the shooting patch selection sequence is also investigated. Theoretical and experimental evaluation is also presented to verify that the proposed parallelization scheme yields equally good performance on multicomputers implementing the simplest (e.g. ring) as well as the richest (e.g. hypercube) interconnection topologies. This paper also proposes and presents a parallel load re-balancing scheme which enhances our basic parallel radiosity algorithm to be usable in the parallelization of radiosity methods adopting adaptive subdivision and meshing techniques. Copyright © 1996 Elsevier Science Ltd.