Abstract
Abstract This thesis presents a real-time soft shadow algorithm for supporting the rendering of soft and hard shadow (similar to all-frequency shadow in Pre-computed Radiance Transfer (PRT)) in dynamic scenes. The thesis, at the same time, supports local area lights of arbitrary shape. The method includes preprocess and rendering part, which is motivated by the work Shadow Fields by Zhou et al. [10], and is also based on from-region visibility works. The main idea is to replace the 5D shadow fields with ray space footprint maps (derived by Leyvand et al. [13]), which originally solved from-region visibility problems. For each occluder and local light source, a ray-space footprint map can be built separately in the pre-process. In runtime, we only need to lookup these pre-computed maps to calculate shadow value for each visible fragment. For overcoming the difference between visibility and shadow problems, the key difficulties are: 1) changing Ray Space Factorization [13] to a novel algorithm with preprocess version for enhancing the performance of rendering 2) providing a novel fusion loop algorithm to preprocess each scene entity for keeping constant number of ray space footprint maps, which guarantees the real-time performance, low memory cost, and quality for soft shadow with local area lights of arbitrary shape. Keywords Pre-computed radiance transfer, From-region visibility, Ray space, Occluder, Fusion.