Cone normal stepping

Abstract

This dissertation examines several methods of relief mapping, such as parallax mapping and cone step mapping, as well as methods for soft shadowing and ambient occlusion of relief maps. Ambient occlusion is an approximation of global illumination that only takes occlusion into account. New relief mapping methods are introduced to bridge the gap between distance elds and cone maps. The new methods allow calculating approximate distance elds from their cone map approximate ambient occlusion and soft shadows. The new methods are compared with linear, binary, and interval search as well as variants of cone mapping, such as relaxed cone mapping and quad cone mapping. These methods were evaluated with regards to performance and accuracy and were found to be similar in performance and accuracy than the existing methods. The new methods did not outperform existing methods on the tested scenes, but the new methods make use of approximate distance elds and remove the maximum cone angle limitation. It was also shown that in most cases linear search with interval mapping performed the best, given the error metric used.