Autodesk LIGHTSCAPE, Manual

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A
Light and Color
This appendix describes light and color and provides information to help you
produce higher-quality pictures. It also explains some of the current limitations
of Lightscape.
Overview
Light is part of the physical world; color is our
perception of the light that reaches the eye. Radiosity
simulates the propagation of light throughout an
environment. The image created after the solution
should create the same visual response as the real
scene. This can be difficult to achieve because
certain phenomena are not well understood and
because current solutions require processing power
beyond today’s availability. The rendering process is
primarily concerned with the simulation of light and
the display of color.
Light: The Physical World
The radiosity and ray tracing methods used by
Lightscape attempt to model the physical properties
of light, its propagation through the environment,
and its interactions with materials. An under-
standing of what light is and how it interacts with
materials makes it easier to create realistic looking
images. The Lightscape radiosity and ray tracing
methods give the best results if the inputs to the
simulation are physically accurate. This section
describes what light is, how it is represented, how
materials affect it, and how it is used in computer
graphics.
Spectra
Light, or the visible spectrum, is electromagnetic
radiation with wavelengths between 380 and 780
nanometers (nm). Intensity spectra are descriptions
of light. At each wavelength they give the intensity of
the light at that wavelength. Spectra are often repre-
sented as spectral curves or graphs showing the
intensity at each wavelength.