

Yes I have written something that creates meshed fractal terrain
surfaces for exactly the purpose you require, importing into 3D
modelling packages. Be warned, the data content is high and brings
many packages to their knees. We use it primarily for MicroStation
but it exports DXF, as well as other formats, so you should be OK.
You can get it from my FTP mirror site in the US.
It is
   wuarchive.wustl.edu
my stuff is located in the
   mirrors/architec
directory. Please FTP the README file first.

-- 
Paul D Bourke                       School of Architecture, Property, Planning
pdbourke@ccu1.auckland.ac.nz        The University of Auckland
Ph:   +64 -9 373 7999 x7367         Private Bag 92019
Fax:  +64 -9 373 7410               Auckland, New Zealand