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Procedurally generate pirate treasure maps.
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README.md
alpha_shape.py
graph.py
layers.py
main.py
poisson_disc.py
requirements.txt
xkcd.py

README.md

Pirate Maps

Procedurally generated pirate treasure maps. X marks the spot!

Example

Dependencies

I used several excellent third party libraries...

  • cairo for rendering
  • colour for color interpolation
  • noise for simplex noise
  • Pillow for saving debug images of noise layers
  • pyhull for delaunay triangulation
  • Shapely for all kinds of 2D geometry operations

How to Run

The script will generate several random maps and save them as PNG files.

git clone https://github.com/fogleman/PirateMap.git
cd PirateMap
pip install -r requirements.txt
python main.py

How it Works

It took me a while to decide on an approach for generating the land masses. I didn't want to just generate some simplex noise, threshold it and render it. I wanted to actually compute a polygonal shape that I could do further operations on. So here's how that works...

  • generate a layer of simplex noise with several octaves, with decreasing values as the edge of the image is approached
  • fill the screen with randomly positioned points evenly spaced using the poisson disc algorithm
  • filter the poisson points to those where the corresponding noise value is above some threshold
  • take these points and compute a "concave" hull or alpha shape with them

Shapely's buffer function is used heavily for padding or cleaning up shapes.

I also wrote an xkcdify function to add some perturbations to some of the polygons, namely the different water color gradations.

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