An advanced optical ray tracing software was developed for the extensive study of Complex Fenestration Systems. Using an algorithm mixing two and three-dimensional approaches, very fast and accurate computation of large number of rays in complex geometries could be performed. In this paper it is described how the software was extended to study the impact of such systems on daylighting and thermal properties in a space. The simulation was made location dependent and an estimate of illumination values and temperatures in a space was added. For accurate and rapid results, diffuse and direct radiation were separated and a matrix multiplication approach was used to derive daylight availability and hourly thermal loads. A novel glazing that was engineered with this simulation tool and combines the functions of daylighting, glare protection, and seasonal thermal control while conserving a clear view will illustrate the performance study.