Selmo, D.Musante, F.Rossi, M.S. Battiato and G. Gallo and F. Stanco2014-01-272014-01-2720063-905673-58-4https://doi.org/10.2312/LocalChapterEvents/ItalianChapConf2006/219-224In this work we focus our attention on real-time direct illuminance values computation using dedicated 3D graphics hardware compatible with OpenGL 2 standard. Our method works with real light intensity distribution measured for lighting fixtures by enconding it in a texture for GPU data comunication. Illuminance values are reprensented in real-time by using a perceptual based colour scale. Illuminance computation is limited to direct light. This is not a severe limitation for exterior and road lighting design, and nevertheless it is a useful project parameter for interior lighting design too.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Colour, shading, shadowing, and texture J.6 [Computer Applications]: Computer-aided design (CAD)