System and method of modeling optical systems (339). Experimental data representative of exisitng systems may be used for ray-tracing exisitng optical system. Generalized models may be developed to model multiple stages having multiple elements in an optical system. Graphical user interfaces enable generalized model parameter entry, model execution (420), model editing, and graphical output (400) of ray-tracing results.
 The United States Government has rights in this invention under Contract No. DE-AC36-99G010337 between the United States Department of Energy and the National Renewable Energy Laboratory, a Division of the Midwest Research Institute.