TopologyException: found non-noded etc. question on GDAL 1.9.2-GEOS 3.3.6

[julius6]

Hi all, I'm getting this error during S57 dataset clipping for conversion to ShapeFiles. This error is absolutely correct (actually the charts have small intersections), so no issues at all with GDAL/GEOS. But the problem is that in most cases the geometry where the error is detected seems not returned to the caller. In other words, some geometry feature is lost at the end, just the ones where the error is. My question is: GDAL/GEOS use a fully topology kind of controls parsing geometries. Is there any configuration option, any workaround or so that allows us to convice GEOS to use a simplified topology model where small intersections are accepted?

Thank you very much.

[Even Rouault]

My question is: GDAL/GEOS use a fully topology kind of controls parsing geometries. Is there any configuration option, any workaround or so that allows us to convice GEOS to use a simplified topology model where small intersections are accepted?

I don't think so, but this would rather be a question for the GEOS mailing list. And more generally, questions are not appropriate for Trac tickets (you should rather use the mailing list or other online resources).

You might try to use MakeValid (​http://www.gaia-gis.it/gaia-sins/spatialite-sql-4.2.0.html) with the SQL SQLite dialect before doing the clipping.

Something like:

ogr2ogr out.shp in.000 -sql "select makevalid(geometry),* from the_layer" -dialect sqlite -clipdst ....