dxf

[Claire Hay]

I have a piece of DOS software that will strip a *.DXF file and output 
an ascii 

file with the X Y Z point values. 
This file can then be brought into
several other software packages that can do interpolation of the z values
to produce a surface map.  I'm not sure how GRASS can use this file - 
I know it can bring in point (sites) data.  If this program would be of 
use to you let me know and send me a mail address so I can mail it to you.
Oh the program is a DOS application program so file transfer between
DOS and UNIX would be required at some point depending on what kind of
processing you want to run on the data before putting it into GRASS.
What I often do with elevation data that was digitized with  AUTOCAD
is strip the *.DXF file for it's X Y Z  values, interpolate to a surface
in SURFER, and take the ascii surface out file into PMAP.  The SURFER
file could easily be reformated to go into GRASS as a flat ASCII grid
file.  The SURFER file is actually already a flat ascii file except
that it's origin is lower left corner instead of upper left corner
as in raster GIS packages.   Don't know if this helps but if

nothing else better shows up for you let me know.
claire M. Hay, CSU