In this paper we present a procedure to test software ability to describe daylight sources. The method will be applied to Lightscape release 3.2 [1]. The results have been achieved independently from the software developers comparing software results with analytical solutions. The tests deal with: a) definition of the algorithms used to represents different skies; b) influence of sun position; c) ground reflection management. Finally suggestions on how to use Lightscape in your daylight design are given.
In this paper, we use the validation test cases initialized within the subtask C, "Daylight design tools", of IEA SHC Task 21, "Daylight in buildings" to assess the accuracy of a commercial lighting software, Lightscape 3.2. We first analyzed the applicability and the limitations of the IEA 21 test cases, and we concluded some directives for validation test cases in order to guaranty its applicability to assess any lighting software.