8

Material Components 1243
Several different shaders are available. Some of
these are not available for Raytrace material, as
indicated. Blinn is the most general purpose of
these shaders. The others have special purposes,
especially regarding how the material creates
high lights.
•
Anisotropic (page 2–1321)
Createssurfaceswithnoncircular,"anisotropic"
high lights; good for mo deling hair, glass, or
metal.
•
Blinn (page 2–1321)
Creates smooth surfaces w ith some shininess; a
general-purpose shader.
•
Metal (p age 2–1322)
Creates a lustrous metallic effec t.
•
Multi-Layer (page 2–1323)
Creates more complex highlights than
Anisotropic by layering two anisotropic
high lights.
Not available for Raytrace material.
•
Oren-Nayar-Blinn (page 2–1323)
Creates good matte surfaces such as fabric or
terra-cotta; s imilar to Blinn.
•
Phong (page 2–1321)
Creates smooth surfaces with some shininess;
similar to Blinn, but doesn’t handle hig hlights
(especially glancing highlig hts) as well.
•
Strauss (page 2–1324)
Creates both nonmetallic and metallic surfaces;
has a simple set of controls.
Not available for Raytrace material.
•
Tr anslucent (page 2–1326)
Translucent shading is similar to Blinn shading,
butitalsoletsyouspecifytranslucency,where
lightisscatteredasitpassesthroughthe
material. You can use translucency to simulate
frosted and etched glass.
Not available for the Raytrace material.
Material Components
Amaterial’scomponentsdescribeitsvisual
and optical properties. The components in
Architectural m aterial (page 2–1376) are based
on physical qualities; for example, diffuse
color, shininess, transparency, and so on. The
components in a
Standard material (page 2–1309)
include color components, highlight controls,
self-illumination, and opacity. Like the Standard
material, the
Raytrace material (page 2–1353) uses
anonphysicalmodeltodescribesurfaces.
Standard and Raytrace material components vary
depending on which
shader (page 2–1242) you
use.
Yo u c a n a s s i g n m a p s t o m o s t c o m p o n e n t s ,
including color components such as Diffuse,
and value components such as Transparency or
Opacity. Maps can increase the complexity and
realism of the material’s appearance.
Light s and Sha ding
Materials work in combination with lights (page
2–1126)
. The intensity of light that falls on a
surface determines the intensity of color to display.
Three factors contribute to the intensity of light
where it falls on an object:
• Light inten si ty: A lig ht’s original intensity at
its point of origin.
• Angl e of inci dence: The more a surface
inclines away from the light source, the less light
it receives and the darker it appears. The angle
between a ray of light and the
face normal (page
3–1074)
of a surface is the angle of incidence
for that face.
When the angle of incidence is 0 degrees (that
is, the light strikes the face perpendicularly),