Selected Issues on Material Properties of Objects in Computer Simulations of Floodlighting

Abstract

This paper addresses issues with computer simulation involved in designing illumination for architectural structures. In particular, the reflectance and transmittance of materials were studied with respect to their influence on luminance values, thus directly the power levels for luminaires applied under particular projects. Raster images derived from digitally processed daytime pictures were used to precisely define material properties. Bitmaps were tested with regard to measuring and editing materials with a widely used graphic application. A real architectural object, the Basilica of the Dormition in Jerusalem, served as the test object. A floodlighting design was performed following a complete analysis of all electrical and photometric parameters. Luminance distributions were analysed comprehensively. Hence, the data allowed for an assessment of the lighting design compliance with guidance given by International Commission on Illumination (CIE) for floodlighting objects and its required standards. The floodlighting utilization factor of the lighting solution developed was also verified, as it is the input parameter for evaluating not only the energy efficiency for the installed lighting system, but also the impact it has on the surroundings, in this case, the project that is to be implemented.