Testing technologies for software systems of optical simulation and realistic computer graphics developed at the Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, are described. The complexity of the products developed (which consist of about 500 software components) and the need to produce a large number of versions (from 50 to 70 versions a year) require the development of an own testing system that would allow one to effectively detect errors and correct them before product release. The testing of computer graphics products has its own specificity, which is the focus of the present study.