Reconstruction of illumination from area luminaires

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Reconstruction of Illumination from Area Luminaires

. This paper is concerned with the efficient reconstruction of illumination from area luminaires. We outline a 2-pass scheme; a lightpass, tracing ray bundles from the luminaires followed by a general eyepass ray trace phase. Special attention is paid during the first pass to the reconstruction of shadows, both umbral and penumbral regions, for general luminaire geometries with no practical restriction on surface reflectance distributions. In order to minimise computation times, adaptive sampling techniques are used to concentrate effort in regions of high illumination gradients and in particular regions exhibiting discontinuities. Illumination functions are reconstructed from samples in a manner related to adaptive kernel density estimation techniques. 1 Introduction Recently the illumination from specular surfaces has been separated from other transport mechanisms and dealt with as a pre-processing stage. Arvo [Arv86] traces rays from the light sources and records these rays on surf..