Sorry about that. What I meant by "any number of ways" is that the way I generate elevations works on any shape of coastline. In the demo, the default is to gen

Sorry about that. What I meant by "any number of ways" is that the way I generate elevations works on any shape of coastline. In the demo, the default is to generate the coastline the way you describe — Perlin noise minus distance from the center of the map. I also have a "Radial" option that draws a bunch of sine waves in polar coordinates, and a "Blob" option that draws my blob logo. It would work just as well if you hand-draw it or use a pizza box or scatter macaroni. I should probably add an explanation to the article.