Cornell University Program of Computer Graphics
A framework for the analysis of error in global illumination algorithms.James Arvo, Kenneth Torrance, and Brian Smits.
In Andrew Glassner, editor, SIGGRAPH 94 Conference Proceedings, Computer Graphics Proceedings, Annual Conference Series, pages 75--84. ACM SIGGRAPH, ACM Press, July 1994.
In this paper we identify sources of error in global illumination algorithms and derive bounds for each distinct category. Errors arise from three sources: inaccuracies in the boundary data, discretization, and computation. Boundary data consist of surface geometry, reflectance functions, and emission functions, all of which may be perturbed by errors in measurement or simulation, or by simplifications made for computational efficiency. Discretization error is introduced by replacing the continuous radiative transfer equation with a finite-dimensional linear system, usually by means of boundary elements and a corresponding projection method. Finally, computational errors perturb the finite-dimensional linear system through imprecise form factors, inner products, visibility, etc., as well as by halting iterative solvers after a finite number of steps. Using the error taxonomy introduced in the paper we examine existing global illumination algorithms and suggest new avenues of research.
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