“Ramp” is a parametric texture.
The Ramp texture procedure is used to create a texture map that graduates from one color to another or through a series of colors. Effects ranging from simple stripes to geometric patterns and mottled surfaces are easily created by the choice of Ramp and Interpolation types. By default, the Ramp texture graduates from black to red to blue in a linear, horizontal (V ramp) fashion. When applied to a Bump map however, the colors in the ramp are represented as a gray scale.
The Ramp texture is commonly used as a two-dimensional Environment background, but can also be used with other map types such as the transparency map for special effects. When used as the source file for an Environmental Sphere texture, you can create very natural-looking sky and horizon effects. When used as the source file for a Projection texture, you can create very natural woodgrain, marble and rock effects.
| Argument Name | Absolute Range | Useful Range | Default | Description |
| ramp_type | not applicable. | V_RAMPU_RAMPDIAGONALRADIALCIRCULARBOXUV_RAMPTARTANFOUR CORNER | V_RAMP | There are nine different ramp types to choose from. |
| interpolation | not applicable | NONELINEAR_RAMPRAMP_UPRAMP_DOWNSMOOTHBUMP_OUTBUMP_IN | LINEAR_RAMP | Affects the way colors in the ramp are interpolated. There are seven interpolation types to choose from, including a selection for no interpolation, which causes each color to be displayed as a solid band. |
| ramp_color | -infinity, infinity | 0, 256 | 0.0, 0.0, 0.0 | Determines the RGB value of the ramp at its given position |
| position | 0, 1 | 0, 1 | 0.0 | Gives the placement of a given ramp color. |
| u_wave | -infinity, infinity | -0.5, 0.5 | 0.0 | Controls the amplitude of a sine wave offset of the texture in the U direction. |
| v_wave | -infinity, infinity | -0.5, 0.5 | 0.0 | Controls the amplitude of a sine wave offset of the texture in the V direction. |
| noise | -infinity, infinity | 0, 1 | 0.0 | Affects the amount that the texture is offset in the U and V direction by two-dimensional noise. |
| noise_frequency | -infinity, infinity | 0, 1 | 0.5 | Controls how fine-grained the noise is. However, if the U and V repeat values of the texture area are greater than 1, then noise does not cause a repeat of the pattern. |
| hue_noise | -infinity, infinity | 0, 1 | 0.0 | Offsets the hue value (mottles the color). |
| sat_noise | -infinity, infinity | 0, 1 | 0.0 | Offsets the “whiteness” (creates a weathered look). |
| val_noise | -infinity, infinity | 0, 1 | 0.0 | Offsets the “blackness.” |
| hue_noise_frequency | -infinity, infinity | 0, 1 | 0.5 | Controls how fine-grained the hue noise will be. |
| sat_noise_frequency | -infinity, infinity | 0, 1 | 0.5 | Controls how fine-grained the saturation noise will be. |
| val_noise_frequency | -infinity, infinity | 0, 1 | 0.5 | Controls how fine-grained the value noise will be. |
| urepeat | -infinity, infinity | -10.0, 10.0 | 1.0 | # of copies in u direction within coverage area. |
| vrepeat | -infinity, infinity | -10.0, 10.0 | 1.0 | # of copies in v direction within coverage area. |
| uoffset | -infinity, infinity | -1.0, 1.0 | 0.0 | U offset repeat within coverage area |
| voffset | -infinity, infinity | -1.0, 1.0 | 0.0 | V offset repeat within coverage area |
| ucoverage | -infinity, infinity | 0.0, 1.0 | 1.0 | amount of U surface to be textured |
| vcoverage | -infinity, infinity | 0.0, 1.0 | 1.0 | amount of V surface to be textured |
| utranslate | -infinity, infinity | -1.0, 1.0 | 0.0 | amount of U coverage area to be moved. |
| vtranslate | -infinity, infinity | -1.0, 1.0 | 0.0 | amount of V coverage area to be moved. |
| uwrap | TRUE FALSE | TRUE | flag to wrap texture around U boundaries of coverage area. | |
| vwrap | TRUE FALSE | TRUE | flag to wrap texture around U boundaries of coverage area. | |
| worldspace | TRUE FALSE | FALSE | flag to use world space texture mapping | |
| rotate | -infinity, infinity | -360.0, 360.0 | 0.0 | angle coverage area to be rotated |
| mirror | TRUE FALSE | FALSE | flag to match edges of texture |
