[GRASSLIST:8055] Re: V.digit (GRASS): Layer disapears, using QGIS
as front end
holl at gdf-hannover.de
Thu Aug 25 01:54:59 EDT 2005
On Wed, 24 Aug 2005 09:17:52 -0400 Dave Sampson <gis at watersheds.ca>
> Hey GRASS/QGIS folks.
> I have a base vector layer for a lake that I wish to digitize over.
> When I use v.digit and create a new layer, my display blanks, hiding
> the lake layer. The VIEW does not change extents as I can display the
> new dumby vector over the old one after I SAVE AND EXIT. However its
> hard to line up a land feature to the shoreline without seeing the
> shoreline while digitizing.
> My work around is to make a dumby vector in GRASSA and then digitize
> in QGIS. Which brings up a second issue. If I delete the dumby vector
> in QGIS before making a new one, the vector file becomes currupt for
> both QGIS and GRASS. So you start with one dumby vector in GRASS,
> create a new less obtrusive dumby vector in QGIS and delete the old
> dumby GRASS vector before you start digitizing. To say the least, a
> few extra steps that would be nice to avoid. This would be a major
> drawback to using GRASS/QGIS in a production digitizing scenario.
> How do I use GRASS to digitize a new layer over an existing one. Do I
> need to provide more info to this list?
To digitazie from a backdrop-map you could use the following command:
v.digit -n <mynewvectormap> -bgcmd='d.rast backdropmap;d.vect
Perhaps this is what you need?
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