This work is framed within the context of computer graphics starting out from the intersection of three fields: rendering, information theory, and complexity. Initially, the concept of scene complexity is analysed from a geometric visibility point of view. Then, the main focus of this dissertation, the development of new refinement criteria for the global illumination problem is presented. Firstly, based on Shannon entropy, a set of pixel measures are defined. They are applied to supersampling in ray-tracing as refinement criteria, obtaining a new entropy-based adaptive sampling algorithm...