Information
- Publication Type: Technical Report
- Workgroup(s)/Project(s): not specified
- Date: April 2000
- Number: TR-186-2-00-04
- Keywords: first-shot, finite-element techniques, global methods, Monte-Carlo quadrature, stochastic iteration, Non-diffuse global illumination
Abstract
This paper presents a method that can replace the small and medium size lightsources by their effect in non-diffuse global illumination algorithms. Incoming first-shot is a generalization of a preprocessing technique called the first-shot that was developed for speeding up global diffuse radiosity algorithms. Alternatively, it can also be approached as a generalization of the direct-lightsource computation involved in gathering type methods. In order to reduce the prohibitive memory requirements of the original first-shot when it is applied to non-diffuse scenes in a direct manner, the proposed new method computes and stores only the incoming radiance generated by the lightsources and the reflected radiance is obtained from the incoming radiance on the fly taking into account the local BRDF. Since the radiance function of the reflection is smoother and flatter than the original lightsource function, this replacement makes the integrand of the rendering equation have significantly smaller variation, which can speed up global illumination algorithms. The paper also discusses how the first-shot technique can be built into a stochastic iteration algorithm using ray-bundles, and provides run-time statistics.Additional Files and Images
Weblinks
No further information available.BibTeX
@techreport{Szirmay-2000-NDFS, title = "Incoming First-Shot for Non-Diffuse Global Illumination", author = "L\'{a}szl\'{o} Szirmay-Kalos and Mateu Sbert and Roel Martinez and Robert F. Tobler", year = "2000", abstract = "This paper presents a method that can replace the small and medium size lightsources by their effect in non-diffuse global illumination algorithms. Incoming first-shot is a generalization of a preprocessing technique called the first-shot that was developed for speeding up global diffuse radiosity algorithms. Alternatively, it can also be approached as a generalization of the direct-lightsource computation involved in gathering type methods. In order to reduce the prohibitive memory requirements of the original first-shot when it is applied to non-diffuse scenes in a direct manner, the proposed new method computes and stores only the incoming radiance generated by the lightsources and the reflected radiance is obtained from the incoming radiance on the fly taking into account the local BRDF. Since the radiance function of the reflection is smoother and flatter than the original lightsource function, this replacement makes the integrand of the rendering equation have significantly smaller variation, which can speed up global illumination algorithms. The paper also discusses how the first-shot technique can be built into a stochastic iteration algorithm using ray-bundles, and provides run-time statistics.", month = apr, number = "TR-186-2-00-04", address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", institution = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", note = "human contact: technical-report@cg.tuwien.ac.at", keywords = "first-shot, finite-element techniques, global methods, Monte-Carlo quadrature, stochastic iteration, Non-diffuse global illumination", URL = "https://www.cg.tuwien.ac.at/research/publications/2000/Szirmay-2000-NDFS/", }