The Materials and Geometry Format
Version 1.0, May 1995
Greg Ward,
Lawrence Berkeley Laboratory,
GJWard@Lbl.Gov
MGF was developed initially to support detailed geometric
description of light fixtures for the IESNA luminaire data standard,
publication LM-63.
Existing standards for geometric description were either too
cumbersome (e.g.
Radiance)
or did not include physical materials (e.g. IGES).
It was noted early on that a standard able to fully describe
luminaires would necessarily be
capable of describing other objects as well; indeed whole
environments could be defined this way.
Since the descriptions would be physical, they could serve as input
to both lighting simulation and rendering software.
A standard language for describing the appearance of physical
objects has been lacking for some time, and current efforts in this
direction (i.e. STEP) seem several years away from fruition.
(There are other languages for describing realistic scenes
that deserve mention here, such as
VRML and the Manchester Scene Description Language,
but none give specific attention to physical
material properties and are thus unsuitable for lighting
simulation.)
In short, we saw this as an opportunity to offer the lighting and
rendering community a simple and easy-to-support standard for
describing environments in a physically valid way.
Our hope is that this will promote sharing color, material and object
libraries as well as complete scene descriptions.
Sharing libraries is of obvious benefit to users and software
developers alike.
Sharing scenes should also permit
comparisons between rendering systems and
intervalidation of lighting calculations.
As anyone who works in this field knows, modeling is the most
difficult step in creating any simulation or rendering, and there is
no excuse for this data being held prisoner by a proprietary data
format.
Application Notes