[Freegis-list] 3D shapefiles

[Markus Neteler]

On Wed, Apr 13, 2005 at 09:00:52AM +0200, Paolo Cavallini wrote:
> Hi all.
> Does anybody know whether it is possible to work (import-export) with 3D 
> shapefiles, with gass or other free software?

Funny - I tried the same yesterday.
Generally yes for GRASS 6:

Note: import into any location (e.g., Spearfish sample location)

################ 3D DXF/DWG example
#Example: 3D DXF from http://www.3dcafe.com/asp/architex.asp#DXF
v.in.dwg -z in=dxf/WATRTOWR.DXF out=watertower

v.info watertower
...
 |  Map is 3D:              1
 |            N: 584.584       S: -599.734    
 |            E: 579.789        W: -584.248  
 |            B: -1873.830        T: 594.000  
...

# -> unprojected DXF (use v.transform to geocode it)

g.region vect=watertower res=10 -pa

#take B (bottom) as minimum elevation:
r.mapcalc "plane=-1873.830"
r.colors plane col=gyr

#look at it:
nviz plane vect=watertower

#Result, something like this:
# http://mpa.itc.it/markus/grass60/nviz_watertower3D.png


#############

3D SHAPE: If PolygonZ is properly used it should
work as well (v.in.ogr). Currently I don't have
and true 3D SHAPE file to try.

Best

 Markus