Material
(Term used in the Radiance software)
In Radiance, materials define the basic properties
of every surface.
There are several classes
of materials:
- Plastic like materials are opaque and can have
diffuse and specular reflection properties. Specularly
reflected light keeps the color of the light source.
-
Metal like materials are similar to plastic, but
specularly reflected light takes material color.
-
Transparent materials can have specular and diffuse
reflecion as well as transmission properties.
-
Glass and glass like materials specularly transmit
and reflect light and also have refractive properties.
-
BRTDs,
Bidirectional Reflection and Transmission Descriptions
are the most general "material" type. All reflective and
transmissive properties can be controlled exactly for
light entering and exiting in any direction.
-
Mist is used to model voluminous participating media like
smoke, fog or "muddy water".
-
There are some other specialised material types to
model prismatic glazings for light redirection.
-
Most material types exist in varieties that allow
for anisotropic definition of their properties, or
that can take be influenced from functions or data
files.
-
Antimatter is a special "material" type,
which subtracts from other materials. This works best
when applied to objects of simple shape and closed
volume, which intersect with other objects.
Radiance allows modifiers to be applied
to all materials that can influence the color,
manipulate the normal vector of the surface
or blend two materials or modifiers into each
other with a defined function.