Tessera is a Unity addon for procedurally generating 3d tile-based levels and builds. Get it here.
 
  Tessera works by running the Wave Function Collapse algorithm. This algorithm is a powerful technique for
  generating maps from complicated tile sets with tight controls on behaviour.
  
For help, contact boris@boristhebrave.com.
These docs contains tutorials and class based documentation for Tessera v3.4.1.