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Procedural texturing: Difference between revisions
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→Building blocks of procedural texturing
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From the superposition of several sparse dot distributions, dense dot distributions can be created. Note that a sparse dot distribution does not average to 0.5 but, dependent on the details of the implementation, to a much lower value. | From the superposition of several sparse dot distributions, dense dot distributions can be created. Note that a sparse dot distribution does not average to 0.5 but, dependent on the details of the implementation, to a much lower value. | ||
=== Stratified noise === | |||
Stratified noise uses the terrain mesh altitude information to draw bands of constant altitude which each have a random number associated. The bands are then distorted in width by an altitude-dependent random number and modulated with an (xy)-position dependent random number. Stratified noise is rather useful for some types of rock formations. | |||
=== Domain noise === | |||
The idea of domain noise is to segment the terrain into discrete patches, each of which has a random number associated. Unlike for Perlin noise, the number is not interpolated, it suddenly jumps at the domain boundary to a different value. | |||
The FG implementation of domain noise uses a regular grid at some wavelength, then distorts the grid points by random numbers and uses [http://en.wikipedia.org/wiki/Voronoi '''Voronoi tiling'''] to determine the domains within the distorted grid. This creates domains with a controllable irregularity which are all about the same size. | |||
Domain noise is very useful for man-made patterns, e.g. managed forest, agriculture or cities. | |||
=== Slope line noise === | |||
For slope line noise, the terrain is segmented in patches, and based on the normal of the terrain, a line along the direction of steepest descent is drawn on the patch, with precise line position and thickness modulated by random numbers. This type of noise mixed into Perlin noise can give a good impression of snow distributions on steep slope or erosion patterns on terrain. | |||
=== Terrain probing functions === | === Terrain probing functions === | ||