Applying Textures to Geometries
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Color Components
A texture image can have up to four components per texture element:
• A one-component image consists of a luminance value, L
t
. One-component textures
are often referred to as intensity maps. For example, an image of a statue could use
polygons of different intensities to shade and provide detail.
• A two-component image consists of luminance, L
t
, and transparency, A
t
. For example,
you could create an architect’s diagram of a house using polygons of different
intensities to give detail to the building materials and then vary the transparency of
the polygons to see through the building materials.
• A three-component image consists of a set of RGB values, referred to as a color triplet,
C
t
. For example, any color image is at least a three-component image.
• A four-component image consists of an RGB (or C
t
) set of values, and transparency, A
t
.
The “t” subscript denotes the transparency or the color of the texture. For example,
you could create an architect’s diagram of a house using a variety of colors and
transparencies.
The color components work with the texture environments in the following way:
• MODULATE works with any texture file.
• BLEND works with one- to four-component textures.
• REPLACE works with three- or four-component textures.
• ADD works with three- or four-component textures.
• DECAL works with three- or four-component textures.
Tip: MODULATE works best with bright materials because the texture intensity is
reduced by the factor of the geometry’s intensity.
