A whole variety of different techniques for simulating global illumination in virtual environments have been developed over recent years. Each technique, including Radiosity, Monte-Carlo ray- or photon tracing, and directional-dependent Radiance computations, is best suited for simulating only some special case environments. None of these techniques is currently able to efficiently simulate all important lighting effects in non-trivial scenes. In this paper, we describe a new approach for efficiently combining different global illumination algorithms to yield a composite lighting simulation: Lighting Networks. Lighting Networks can exploit the advantages of each algorithm and can combine them in such a way as to simulate lighting effects that could only be computed at great costs by any single algorithm. Furthermore, this approach allows a user to configure the Lighting Network to compute only specific lighting effects that are important for a given task, while avoiding a costly s...