If you have some other 3D software, you can create a landscape object as you wish and import it into SH3D, as i show here:

http://www.sweethome3d.com/support/foru ... hread,3388

i use Cinema4D. I believe blender is also capable of creating random landscape. And bryce is free in some versions also.
no need to blame Puybaret in this case IMHO