best way is to play with the generator. Insert terrain, then in the modeller window, add a layer to the terrain. It is null generator. Then choose from the list. It is good to set the preview not to small, let say 513, to see how details appear. For getting your phantasie in action, remove in the standard terrainlayers all except the first. Play a bit with the bumpsettings and do offen a testrender. Johannes