Efficient Product Sampling using Hierarchical Thresholding
Fabrice Rousselle,
Petrik Clarberg,
Luc Leblanc,
Victor Ostromoukhov,
and
Pierre Poulin
Proc. Computer Graphics International 2008, June 2008
The Visual Computer, 24 (7), pp. 465-474, July 2008.
Abstract
We present an efficient method for importance
sampling the product of multiple functions. Our algorithm
computes a quick approximation of the product
on-the-fly, based on hierarchical representations of the
local maxima and averages of the individual terms. Samples
are generated by exploiting the hierarchical properties
of many low-discrepancy sequences, and thresholded
against the estimated product. We evaluate direct illumination
by sampling the triple product of environment
map lighting, surface reflectance, and a visibility function
estimated per pixel. Our results show considerable noise
reduction compared to existing state-of-the-art methods
using only the product of lighting and BRDF.
Keywords
Importance sampling, rejection sampling, multiple functions,
ray tracing, visibility.
BibTeX entry
@article{RCLOP-vc2008,
title = "Efficient Product Sampling using Hierarchical Thresholding",
author = "Fabrice Rousselle and Petrik Clarberg and Luc Leblanc and Victor Ostromoukhov and Pierre Poulin",
booktitle = "The Visual Computer",
year = 2008,
month = jul,
pages = "465--474",
volume = 24,
number = 7
}
Online version
Adobe PDF version of the paper
Presentation slides (pdf)
Video lower quality (avi)
Video higher quality (avi).
