Light Transport in Realistic Rendering: State-of-the-Art Simulation Methods

The modern realistic computer graphics is based on physically correct lighting simulation. One of the main and computationally difficult problems is the calculation of light transport or global illumination, i.e. the distribution of light in a virtual scene taking into account multiple reflections, light scattering and various interactions of light with the scene objects. This problem is studied in hundreds of books and papers. They describe dozens of computational methods and their modifications. Our survey not only lists and briefly describes them but also gives some kind of a “map” of existing works that helps the reader to find one’s bearings, understand the advantages and drawbacks of these methods and thus select an appropriate basic approach. Special attention is paid to such characteristics of the methods as their robustness and universality with respect to models, the clarity of their verification, the possibility of efficient implementation on GPUs and the constraints imposed on the scene or illumination phenomena. In contrast to existing surveys, we try to analyze not only the efficiency of the methods but their limitations and the complexity of software implementation as well. In addition, the results of the authors' own numerical experiments that illustrate some of our conclusions are presented.