and Rendering System
Gregory J. Ward / GJWard@lbl.gov
Luminance is a directional quantity, and its value
is strongly determined by a material's reflectance/transmittance
If luminance is calculated using a Lambertian (i.e. diffuse)
highlights and reflections are ignored and the result can easily be
wrong by a hundred times or more.
We cannot afford to lose directional information if we hope to use
our simulation to evaluate visual performance, visual comfort and
A global illumination program is only as general as its local
The standard model of ambient plus diffuse plus Phong specular is
not good enough for realistic image synthesis.
includes the ability to model arbitrary reflectance and
transmittance functions, and we have also taken empirical measurements of
materials and modeled them successfully in our system .