perlin()

Syntax

perlin(x)
perlin(x, y)
perlin(x, y, z)
perlin(x, y, z, seed)

Returns a noise value from 0.0 to 1.0 (roughly) for 1, 2 or 3 dimensional coordinate. The default seed it samples from is 0, but seed can be specified as a 4th argument as well. In case you need 1D or 2D noise values with custom seed, use null for y and z, or z arguments respectively.

Perlin noise is based on a square grid and generates rougher maps comparing to Simplex, which is creamier. Querying for lower-dimensional result, rather than affixing unused dimensions to constants has a speed benefit,

Thou shall not sample from noise changing seed frequently. Scarpet will keep track of the last 256 perlin seeds used for sampling providing similar speed comparing to the default seed of 0. In case the app engine uses more than 256 seeds at the same time, switching between them can get much more expensive.