Fast Approximate Quantitative Visibility for Complex Scenes

Ray tracing and Monte-Carlo based global illumination, as well as radiosity and other finite-element based global illumination methods, all require repeated evaluation of quantitative visibility queries, such as (i) what is the average visibility between a point (a differential area element) and a finite area or volume; or (ii) what is the average visibility between two finite areas or volumes. In this paper, we present a new data structure and an algorithm for rapidly evaluating such queries in complex scenes. The proposed approach utilizes a novel image-based discretization of the space of bounded rays in the scene, constructed in a preprocessing stage. Once this data structure has been computed, it allows us to quickly compute approximate answers to visibility queries. Because visibility queries are computed using a discretization of the space, the execution time is effectively decoupled from the number of geometric primitives in the scene. A potential hazard with the proposed appr...

• Type: Conference
• Year: 1998
• Where: CGI
• Authors: Yiorgos Chrysanthou, Daniel Cohen-Or, Dani Lischinski
• Keywords: CGI 1998, Computer Graphics, Data Structures, Global Illumination, Visibility Queries