Isolux curves on the diffuse reflectance of light on concave dihedral angle

Understanding the lighting distribution is very important even today, when there are available some simulation software. Building a solution for a lighting system, impose to start from an elaborated initial solution, and at every step it is necessary the interpretation of the results. The main hypothesis of the paper consists in the possibility that some errors could be present in these simulations software, due to the estimation method. This paper analyses the particular case of the dihedral angle between planes, where the inter reflections generates a particular shape for isolux curves. These reflections generate a kind of continuity for illuminance, but only for concave dihedral angle between planes. Starting from DIALux simulations, where the problem was found, authors were using some original MATLAB functions and some comparisons are made, in order to validate the simulations and understanding the lighting configurations. The conclusions are useful for particular simulations, when local reflections described by isolux curves must be interpreted.