Computing the scattering properties of participating media using Lorenz-Mie theory



AbstractThis paper introduces a theoretical model for computing the
scattering properties of participating media and translucent
materials. The model takes as input a description of the components
of a medium and computes all the parameters necessary to render it.
These parameters are the extinction and scattering coefficients, the
phase function, and the index of refraction. Our theory is based on
a robust generalization of the Lorenz-Mie theory. Previous models
using Lorenz-Mie theory have been limited to non-absorbing media
with spherical particles such as paints and clouds. Our generalized
theory is capable of handling both absorbing host media and
non-spherical particles, which significantly extends the classes of
media and materials that can be modeled. We use the theory to
compute optical properties for different types of ice and ocean
water, and we derive a novel appearance model for milk parameterized
by the fat and protein contents. Our results show that we are able
to match measured scattering properties in cases where the classical
Lorenz-Mie theory breaks down, and we can compute properties for
media that cannot be measured using existing techniques in computer
graphics.
KeywordsLorenz-Mie theory, participating media, optical properties, appearance modeling, realistic rendering
TypeJournal paper [With referee]
JournalACM Transactions on Graphics (Proceedings of SIGGRAPH 2007)
Year2007    Month July    Vol. 26    No. 3    pp. 60-1--60-10
NoteArticle 60, 10 pages
Electronic version(s)[pdf]
BibTeX data [bibtex]
IMM Group(s)Image Analysis & Computer Graphics