30 Jul
2007
30 Jul
'07
1:15 p.m.
On 7/30/07, Martin Lütke
It uses a chaotic function (ergodic?) that works on integers. In the case of Terrain it uses 2. One for the x and one for y coordinate. It should be infinite for Zooming out. When zooming in one uses interpolation. The drawback(?) is when zooming out is that it becomes more "noisy".
Typically you'd sum different 'octaves' of noise to get a function that's approximately self-similar under scaling, that way it'd be qualitatively similar when zooming in or out. There are many descriptions on the web. Here's one I found: http://local.wasp.uwa.edu.au/~pbourke/texture_colour/perlin/ -- Dan