GIMP Simplex Noise as random coastlines

[RobA]

Hey all-

I'm revisiting a bunch of my old tutorial and GIMP scripts as they are so out of date. While poking around the new GEGL based filters I discovered a new one Filters->Render->Noise->Simplex Noise.

It looks pretty weird at the default settings but if you pull the sale waaaaaaaaay down and the Iteration waaaaaaaaaay up yo get some pretty good looking "mid-scale" coastlines. Here is a sample at a scale of 0.05 and Iterations at 10:

simplex.png

And after a quick select by colour, filling and stroking:

simplex_mappy.png

Seems I've got a bunch more playing around before I figure all the new stuff out

-Rob A>

[waldronate]

Fractals based on simplex noise are interesting, but have the nasty habit of showing equilateral triangle/tetrahedral artifacts in most implementations. Any frequency summation noise will tend to show the underlying character of the basis function in the lowest few octaves, though. Simplex noise is a bit less costly to compute than Perlin noise, which is why it's becoming fairly popular (it also has some patents associated with it that make certain kinds of implementations problematic). For me, the interesting part of most coastline generation is less the noise function and more the thresholding and stroking parts that give the final result. I look forward to seeing the updated script if you decide to publish it.