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Modeling Global Illum ination with R adiosity 51
Radiosity
Radiosity is rendering technology that realistically
simulates the way in w hich light interacts in an
environment.
This topic provides you with a conceptual
overview of what radiosity is and how this
global illumination technique relates to other
renderingtechniquesavailablein3dsMax.This
information will h elp you decide which technique
is most suitable for the visualization task you
want to perform. By more accurately simulating
the lighting in your scene, radiosity offers you
significant benefits over standard lig hts:
•ImprovedImageQuality:Theradiosity
technology of 3ds Max produces more accurate
photometric (page 3–993) simulations of the
lighting in your scenes. Effects such as indirect
light, soft shadows, and color bleeding between
surfaces produce images of natural realism
that are not attainable with standard scanline
rendering. These images give you a better, more
predictable representation of what your designs
wi ll lo ok like under specific lighting conditions.
• More In tuitive Lighting: In conjunction with
radiosity techniques, 3ds Max also provides
a real-world lighting interface. Instead of
specifying lighting intensity with arbitrary
values, light intensity is specified using
photometric units (lumens, candelas, and
so on). In addition, the characteristics of
real-world lighting fixtures can be defined
using industry-standard Luminous Intensity
Distr ibution files (such as IES (page 2–1328),
CIBSE (page 3–921),andLTLI (page 3–964)),
which are obtainable from most lighting
manufacturers. By being able to work with a
real-world lighting interface, you can intuitively
set up the lig hting in your scenes. You can
focus more on your design exploration than on
the computer graphic techniques required to
visualize them accurately.
Top: A scene rendered without radiosity.
Bottom: The same scene rendered w ith radiosity.
Computer Gr a phics R ender in g
The3Dmodelscreatedin3dsMaxcontain
geometric data defined in relationship to a 3D
Cartesian coordinate system, referred to as world
space (page 3–1036).Themodelalsocontains
other information about the material of each of
the objects and the lighting in t he scene. The
image on a computer monitor is made up of many
illuminated dots, called pixels (page 3–995).The
task in creating a computer graphics image of a
geometric model is to determine the color for
each pixel based on the model information and a
specific viewpoint (camera).