PolygonPlacer lets you get an area from a non convex polygon.
DunePainter generates the height of procedural dunes given an area.
PerlinPainter generates the height of perlin noise given an area.
Perlin_noise.js defines the perlin fucntion for PerlinPainter .
disableGarrisonHolder.xml is a special filter to make a buildings ungarrisonable.