Neumann, LaszloNeumann, Attila2014-10-212014-10-2119891467-8659https://doi.org/10.1111/j.1467-8659.1989.tb00450.xMethods for realistic image synthesis are described. Exact mathematical establishment of reflectance models is presented, together with the development of feasible reflectance models meeting the energy balance. A new bidirectional reflectance type, separable reflectance, is introduced. Necessary and sufficient conditions for the iterative solution of the linear equation system of interreflection are presented. Lastly, a new method of inserting numerically defined objects into real optical surroundings is described.10.1111/j.1467-8659.1989.tb00450.x21-34