Ah, right you are -- I added columns x,y,z to the table and then ran v.to.db option=start columns=x,y,z and it worked perfectly. Many thanks!
Nick Cahill
On Nov 28, 2008, at 7:14 PM, Hamish wrote:
Nick wrote:
I have a series of contour vector maps imported from a CAD
program (Microstation). The CAD maps were in 3d, and the 3d
information was successfully imported into GRASS, so the
vectors have line heights as well as length, etc. Now I need
to export these into shapefiles. When I do this, all the
other useless CAD data like line color, style, weight, etc.
is exported as attributes in the .dbf file, but line height
is not -- it is not a field in the mySQL database but is
part of the geometry of the line, if I understand what's
going on here correctly. Is there a way to transfer line
height into the attribute table so I can access and export
it? Many thanks,v.db.addcol + v.to.db ?
note that unless lines are perfectly horizontal (eg elevation contours)
you can not assign a single elevation value to a line's attributes (as
each vertex will have its own value, and the attribute is associated with
the line as a whole), so I would expect in general for it to refuse to try.as for 3D shapefile export, ummm... check the wiki, help pages, and ML
archives. It rings a bell but I've no idea how.Hamish