perlin

Generate Perlin noise.

Perlin noise is a kind of noise with local continuity in space. This can be used to generate patterns with continuity in space and time, e.g. to simulate smoke, fluids, or terrain.

In case more than one octave is specified through the octaves option, Perlin noise is generated as a sum of components, each one with doubled frequency. In this case the persistence option specify the ratio of the amplitude with respect to the previous component. More octave components enable to specify more high frequency details in the generated noise (e.g. small size variations due to boulders in a generated terrain).