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Exploiting visibility correlation in direct illumination

Clarberg, Petrik LU and Akenine-Möller, Tomas LU (2008) In Computer Graphics Forum 27(4). p.1125-1136
Abstract
The visibility function in direct illumination describes the binary visibility over a light source, e.g., an environment map. Intuitively, the visibility is often strongly correlated between nearby locations in time and space, but exploiting this correlation without introducing noticeable errors is a hard problem. In this paper, we first study the statistical characteristics of the visibility function. Then, we propose a robust and unbiased method for using estimated visibility information to improve the quality of Monte Carlo evaluation of direct illumination. Our method is based on the theory of control variates, and it can be used on top of existing state-of-the-art schemes

for importance sampling. The visibility estimation is... (More)
The visibility function in direct illumination describes the binary visibility over a light source, e.g., an environment map. Intuitively, the visibility is often strongly correlated between nearby locations in time and space, but exploiting this correlation without introducing noticeable errors is a hard problem. In this paper, we first study the statistical characteristics of the visibility function. Then, we propose a robust and unbiased method for using estimated visibility information to improve the quality of Monte Carlo evaluation of direct illumination. Our method is based on the theory of control variates, and it can be used on top of existing state-of-the-art schemes

for importance sampling. The visibility estimation is obtained by sparsely sampling and caching the 4D visibility

field in a compact bitwise representation. In addition to Monte Carlo rendering, the stored visibility information

can be used in a number of other applications, for example, ambient occlusion and lighting design. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Visibility, Ray tracing, Photo-realistic rendering, Monte Carlo techniques, Computer graphics, Direct illumination, Control variates
in
Computer Graphics Forum
volume
27
issue
4
pages
1125 - 1136
publisher
Wiley-Blackwell
external identifiers
  • wos:000258223600009
  • scopus:51549103078
ISSN
1467-8659
DOI
10.1111/j.1467-8659.2008.01250.x
language
English
LU publication?
yes
id
49a95691-21a5-4ff4-9044-b1fd4c88cc36 (old id 1152610)
date added to LUP
2008-05-27 10:43:31
date last changed
2017-05-21 03:37:33
@article{49a95691-21a5-4ff4-9044-b1fd4c88cc36,
  abstract     = {The visibility function in direct illumination describes the binary visibility over a light source, e.g., an environment map. Intuitively, the visibility is often strongly correlated between nearby locations in time and space, but exploiting this correlation without introducing noticeable errors is a hard problem. In this paper, we first study the statistical characteristics of the visibility function. Then, we propose a robust and unbiased method for using estimated visibility information to improve the quality of Monte Carlo evaluation of direct illumination. Our method is based on the theory of control variates, and it can be used on top of existing state-of-the-art schemes <br/><br>
for importance sampling. The visibility estimation is obtained by sparsely sampling and caching the 4D visibility <br/><br>
field in a compact bitwise representation. In addition to Monte Carlo rendering, the stored visibility information <br/><br>
can be used in a number of other applications, for example, ambient occlusion and lighting design.},
  author       = {Clarberg, Petrik and Akenine-Möller, Tomas},
  issn         = {1467-8659},
  keyword      = {Visibility,Ray tracing,Photo-realistic rendering,Monte Carlo techniques,Computer graphics,Direct illumination,Control variates},
  language     = {eng},
  number       = {4},
  pages        = {1125--1136},
  publisher    = {Wiley-Blackwell},
  series       = {Computer Graphics Forum},
  title        = {Exploiting visibility correlation in direct illumination},
  url          = {http://dx.doi.org/10.1111/j.1467-8659.2008.01250.x},
  volume       = {27},
  year         = {2008},
}