Information
- Publication Type: Technical Report
- Workgroup(s)/Project(s): not specified
- Date: July 1998
- Number: TR-186-2-98-18
- Keywords: z-buffer, Metropolis method, importance sampling, stochastic iteration, Monte-Carlo and quasi-Monte Carlo integr, global radiance, Rendering equation
Abstract
The paper presents a single-pass, view-dependent method to solve th
e general
rendering equation, using a combined finite element and random
walk approach. Applying finite element techniques, the
surfaces are decomposed into planar patches on which the
radiance is assumed to be combined from finite number of unknown
directional radiance functions by predefined positional basis functions.
The directional radiance functions are then computed by
random walk or by stochastic iteration using bundles of parallel rays.
To compute the radiance transfer in a single direction,
several global visibility methods are considered, including
the global versions of the painter's, z-buffer, Weiler-Atherton's
and planar graph based algorithms.
The method requires
no preprocessing except for handling point lightsources, for
which a first-shot technique is proposed.
The new method is particularly
efficient for scenes including not very specular materials
illuminated by large area lightsources or sky-light.
In order to increase the speed for difficult lighting situations,
walks can be selected
according to their importance. The importance can be explored adaptively
by the Metropolis and VEGAS sampling techniques.
Additional Files and Images
Weblinks
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BibTeX
@techreport{Szir-1998-Glo,
title = "Global Ray-bundle Tracing",
author = "L\'{a}szl\'{o} Szirmay-Kalos",
year = "1998",
abstract = "The paper presents a single-pass, view-dependent method to
solve th e general rendering equation, using a combined
finite element and random walk approach. Applying finite
element techniques, the surfaces are decomposed into planar
patches on which the radiance is assumed to be combined from
finite number of unknown directional radiance functions by
predefined positional basis functions. The directional
radiance functions are then computed by random walk or by
stochastic iteration using bundles of parallel rays. To
compute the radiance transfer in a single direction, several
global visibility methods are considered, including the
global versions of the painter's, z-buffer,
Weiler-Atherton's and planar graph based algorithms. The
method requires no preprocessing except for handling point
lightsources, for which a first-shot technique is proposed.
The new method is particularly efficient for scenes
including not very specular materials illuminated by large
area lightsources or sky-light. In order to increase the
speed for difficult lighting situations, walks can be
selected according to their importance. The importance can
be explored adaptively by the Metropolis and VEGAS sampling
techniques.",
month = jul,
number = "TR-186-2-98-18",
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 = "z-buffer, Metropolis method, importance sampling, stochastic
iteration, Monte-Carlo and quasi-Monte Carlo integr, global
radiance, Rendering equation",
URL = "https://www.cg.tuwien.ac.at/research/publications/1998/Szir-1998-Glo/",
}