[GRASS-user] v.generalize for polygons?

[Hamish]

Hi,

I have a high-res vector area map of regional districts which I wish to generalize. I am having trouble with finding the correct method in v.generalize to use. Currently every thing I try tends to break the area topology and leave only a portion of the now-open boundary.

i.e. it should preserve nodes, only generalize (remove) non-node vertices.
We can assume there is only a single boundary line between areas, so there shouldn't be topological issues. (or at least only in tiny corner cases where the new generalized line overlaps another feature, but that should be easy to fix with v.clean)

the idea is to simplify the map before running v.extrude to get something like this:
http://grass.osgeo.org/grass60/screenshots/images/inc_employ_usa_2002.jpg

but without the 600,000 extruded faces created from every little twist in the coastline.


Hamish