Hi Tobi
When I do the outdoor map, I first add a heightmap with a texture, then I add all the objects that I want on the map, and when I add the objects, I change the geometry of the heightmap to fit the object.
Example: I have a cave, and when I add it to a mountain, I make a "hole" in the mountain geometry to make the cave fit into the mountain.
You can find terrain in the Xith3D package com.xith3d.terrain, or you could take a look on the terrain in the sourceforge.net project Arabian Flights.
Good luck
Alonzo
