Hi, height means hight of the buildings. All buildings can have same height (height=10) or the height of each building is stored in database (hcolumn=building_height)
elevation option stays for placement of the building upon the digital
elevation model.
so, in your case, you have to:
1 - prepare DEM *without* building footprints
2 - transfer building height parameter from raster map to attribute
table of the vector file
3 - run v.extrude as
v.extrude ... hcolumn=column_with_building_height \
elevation=lidar_dem_without_buildings
hope it helps
jachym
[EMAIL PROTECTED] píše v St 17. 10. 2007 v 04:31 +0000:
> I am trying to use v.extrude to generate buildings of varying height. I
> have a vector file with all of the building outlines and I have a
> raster file that contains high resolution height data extracted from
> LIDAR files. I don't understand the function of v.extrude. I tried
> specifying the raster file name in the "elevation=" option but I get
> an error that says I have to either use a constant height in "height="
> or specify an attribute table column with height data in "hcolumn=".
> What does the "elevation" option do? Any suggestions on easy ways to
> populate a height data column from a raster file?
>
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Jachym Cepicky
e-mail: [EMAIL PROTECTED]
URL: http://les-ejk.cz
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