Make sure you’ve read the general notes about all the nodes: Nodes reference

Procedural map

This node creates a map based on procedural noise functions, such as Perlin or Voronoi noises. It is very useful and versatile, and can be used to add interesting patterns to the size of buildings for example, by the simple buildings layout.

To see the result of a map, draw it into a Blender image with a map drawer node.