Adaptive mesh generation for progressive radiosity: A ray-tracing based algorithm.

Abstract

The radiosity method is one of the most popular rendering algorithms. It allows to simulate interreflections of light accurately between surfaces as energy transfers are well designed. However, this algorithm and its derivatives need to break scenes into a relatively large number of small elements to approximate the illumination function. Even with a very large number of elements, not all the illumination effects can be simulated. In fact, there are always artefacts when modelling sharp shadows, besides shadows falling between mesh vertices can be missed entirely. To reduce the computational cost of such methods and to increase the accuracy of the radiosity solution, adaptive mesh generation is well suited. In this paper, we present a ray-tracing based algorithm for adaptive mesh generation which resolves all the illumination problems without lengthening computation time too much. This method allows a small number of initial elements and increases element density in critical locations while solving the illumination problem.