Real Time Depth Sorting of Transparent Fragments

Abstract: Using transparency is an important technique for modelling partial coverage in computer graphics and is used for a variety of effects such as hair, fur, glass, smoke and particle effects. Replacing the per object sorting as the dominant algorithm used in real time 3D engines with anew algorithm with less rendering artifacts could let artists use more transparency and effects in their scenes. This thesis evaluates two algorithms as a possible replacement to the per object sorting algorithm, the per pixel linked list and the weighted blended order-independent transparency (WBOIT) in a visual comparison and a performance evaluation. The results shows that neither of the algorithms are suitable as replacement as a unified and general transparency algorithm but there are cases where the algorithms can be used as a replacement. The per pixel linked list has good visual quality but lacks in performance and can be used in limited scope such as hair renderings. The WBOIT algorithm has good performance but the approximation used can give noticeable errors in color when there is a large difference in depth between transparent objects.