Reconstruction of Illumination from Area Luminaires

This paper is concerned with the e cient 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 rst pass to the reconstruction of shadows, both umbral and penumbral regions, for general luminaire geometries with no practical restriction on surface reectance distributions. In order to minimise computation times, adaptive sampling techniques are used to concentrate e ort 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.