“Mountain” is a parametric texture.
The Mountain texture procedure is used for rendering terrain. The Mountain texture should first be applied to the shader as a Color Map, and then applied again as a Displacement Map. The Color options have no effect on the displacement map and relate only to the color map portion of the procedure. All non-color related options are ignored for the color mapping when the displacement map is applied. The color mapping automatically matches the displacement mapping. The basis of the terrain model is a two-dimensional fractal.
| Argument Name | Absolute Range | Useful Range | Default | Description |
| amplitude | 0, infinity | 0, 1 | 1.0 | Amplitude of fractal |
| rock_roughness | 0, 1 | 0, 1 | 0.707 | Fractal ratio for the rock |
| level_max | 0, infinity | 0, 40 | 20.0 | Maximum allowed iteration level |
| snow_altitude | -infinity, infinity | -1, 1 | 0.5 | Altitude for snow |
| snow_dropoff | 0, infinity | 0, 10 | 2.0 | Rate of dropoff of snow with altitude |
| snow_max_slope | 0, infinity | 0, 3 | 0.8 | Slope above which snow does not stick |
| snow_roughness | 0, 1 | 0, 1 | 0.4 | Roughness of snow |
| boundary_roughness | 0, 1 | 0, 1 | 0.6 | Raggedness of edge of rock/snow border |
| snow_color (triple) | 0, infinity | 0, 255 | 255,255,255 | Color of snow |
| rock_color (triple) | 0, infinity | 0, 255 | 90, 110, 120 | Color of rock |
| 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 |
