L Aszl O Szirmay-kalos

Publications (2)0 Total impact

• Source

  Available from: psu.edu

  Article: Quasi-Monte Carlo Global Light Tracing with Infinite Number of Rays

  L Aszl O Szirmay-kalos, Tibor F Oris, Werner Purgathofer
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  ABSTRACT: The paper presents an efficient method to solve the general rendering equation, using a combined finite element and quasi-random walk approach. Applying finite element techniques, the surfaces are decomposed into planar patches that are assumed to have position independent, but not direction independent (that is non-diffuse) radiance. The direction dependent radiance function is then computed by quasi-random walk. Since quasi-Monte Carlo quadrature is applied here to an integrand of finite variation, this method can take advantage of the superior convergence of quasi-Monte Carlo integration.
  04/2000;
• Source

  Available from: psu.edu

  Article: Importance Driven Quasi-Random Walk Solution of the Rendering Equation

  L Aszl O Szirmay-kalos, Bal Azs Cs Ebfalvi, Werner Purgathofer
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  ABSTRACT: This paper presents a new method that combines quasi-Monte Carlo quadrature with importance sampling to solve the general rendering equation efficiently. Since classical importance sampling has been proposed for Monte-Carlo integration, first an appropriate formulation is elaborated for deterministic sample sets used in quasi-Monte Carlo methods. This formulation is based on integration by variable transformation. It is also shown that instead of multi-dimensional inversion methods, the variable transformation can be executed iteratively where each step works only with 2-dimensional mappings. Since the integrands of the Neumann expansion of the rendering equation is not available explicitely, some approximations are used, that are based on a particle-shooting step. Although the complete method works for the original geometry, in order to store the results of the initial particleshooting, surfaces are decomposed into patches and the patches are interconnected by links.
  04/2000;