# Orientation Lightmaps for Photon Radiosity in Complex Environments

Alexander Wilkie, Robert F. Tobler, Werner Purgathofer
Orientation Lightmaps for Photon Radiosity in Complex Environments
TR-186-2-99-11, April 1999 [paper]

## Information

• Publication Type: Technical Report
• Workgroup(s)/Project(s): not specified
• Date: April 1999
• Number: TR-186-2-99-11
• Keywords: lightmaps, complex scenes, photon radiosity, global illumination

## Abstract

We present a method that makes the use of photon radiosity methods feasi ble for complex scenes when a totally accurate solution is not essential. This is accompl ished by using {\em orientation lightmaps}, which average the illumination of complex obj ects depending on the surface normal. Through this averaging, they considerably reduce th e variance of the stochastic solution. For the use of these specialised lightmaps, which consume comparatively small amounts of memory, no changes have to be made to the actual p hoton tracing algorithm. Also, they can be freely mixed with normal lightmaps and inserte d at any point in the scene description graph. This gives the user good control over the amount of inaccuracy he introduces by their application. The area computations necessary for their insertion are performed using a stochastic sampling method that performs well f or highly complex objects.

No further information available.

## BibTeX

@techreport{wilkie-1999-ORI,
title =      "Orientation Lightmaps for Photon Radiosity in Complex
Environments",
author =     "Alexander Wilkie and Robert F. Tobler and Werner Purgathofer",
year =       "1999",
abstract =   "We present a method that makes the use of photon radiosity
methods feasi ble for complex scenes when a totally accurate
solution is not essential. This is accompl ished by using
{\em orientation lightmaps}, which average the illumination
of complex obj ects depending on the surface normal. Through
this averaging, they considerably reduce th e variance of
the stochastic solution. For the use of these specialised
lightmaps, which consume comparatively small amounts of
memory, no changes have to be made to the actual p hoton
tracing algorithm. Also, they can be freely mixed with
normal lightmaps and inserte d at any point in the scene
description graph. This gives the user good control over the
amount of inaccuracy he introduces by their application. The
area computations necessary for their insertion are
performed using a stochastic sampling method that performs
well f or highly complex objects.",
month =      apr,
number =     "TR-186-2-99-11",
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 =   "lightmaps, complex scenes, photon radiosity, global
illumination",
URL =        "https://www.cg.tuwien.ac.at/research/publications/1999/wilkie-1999-ORI/",
}