Graphics Programs Reference
In-Depth Information
Ramp Texture
A
ramp
is a gradient in which one color transitions into the next color. You've already
seen how useful a ramp can be in positioning materials in a Layered shader. It's also per-
fect for making color gradients, as shown in Figure 7.37.
Use the round handles to select the color and to move it up and down the ramp. The
square handle to the right deletes the color. To create a new color, click inside the ramp.
The Ramp texture is different from the Ramp shader. The Ramp shader automatically has
several Ramp textures mapped to some of its attributes.
Figure 7.37
The Ramp texture
The Type setting allows you to create a gradient running along the U
or V direction of the surface, as well as to make circular, radial, diagonal,
and other types of gradients. The Interpolation setting controls how the
colors grade from one to the next.
The U Wave and V Wave attributes let you add a squiggle to the
U
or
V
coordinate of the ramp, and the Noise and Noise Freq (frequency)
attributes specify randomness for the placement of the ramp colors
throughout the surface.
Using the HSV Color Noise attributes, you can specify random noise
patterns of Hue, Saturation, and Value to add some interest to your tex-
ture. The HSV Noise options are great for making your shader just a bit
different, to enhance its look.
Fractal, Noise, and Mountain Textures
These textures are used to create a random noise pattern to add to an
object's Color, Transparency, or any other shader attribute. For exam-
ple, when creating a surface, you'll almost always want to add a little
dirt or a few surface blemishes to the shader to make the object look
less CG. These textures are commonly used for creating bump maps.
Bulge, Cloth, Checker, Grid, and Water Textures
These textures help create surface features when used on a shader's
Bump Mapping attribute. Each creates an interesting pattern to add to a
surface to create tactile detail, but you can also use them to create color
or specular irregularities.
When used as a texture for a bump, Grid is useful for creating the
spacing between tiles, Cloth is perfect for clothing, and Checker is good
for rubber grips. Placing a Water texture on a slight reflection makes for
a nice poolside reflection in patio furniture.
