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QGIS is a free, open source, cross platform (lin/win/mac) geographical information system (GIS)
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QGIS Clip and Difference - GEOS geoprocessing error: intersection failed. #29167

Closed qgib closed 5 years ago

qgib commented 5 years ago

Author Name: Lene Fischer (@LeneFischer) Original Redmine Issue: 21349 Affected QGIS version: 3.5(master) Redmine category:processing/core

Trying to clip and difference vector layers. But it fails.

Tride both Geopackage and SHP same result. The datasets has been checked in topology checker.

Attached file. Use layer gravplads against gravsted

qgib commented 5 years ago

Author Name: Giovanni Manghi (@gioman)

Hi Lene, there is no "gravplads" layer in the gpkg.

qgib commented 5 years ago

Author Name: Lene Fischer (@LeneFischer)

qgib commented 5 years ago

Author Name: Lene Fischer (@LeneFischer)

qgib commented 5 years ago

Author Name: Lene Fischer (@LeneFischer)

qgib commented 5 years ago

Author Name: Lene Fischer (@LeneFischer)

I have uploadet a smaller geopackage

qgib commented 5 years ago

Author Name: Giovanni Manghi (@gioman)

Just one more case of the inconsistency that we have in the tools to check geometries: as I raised a few times in the past they all yields different results.

If you fix your layers with the "fix geometries" tool (that is based on the excellent st_makevalid) then the operation runs without issues...

qgib commented 5 years ago

Author Name: Lene Fischer (@LeneFischer)

So sorry - I thought that checking with the topology checker was the best method to control features. When there was no errors I didn´t run the fix geometries.

qgib commented 5 years ago

Author Name: Giovanni Manghi (@gioman)

Lene Fischer wrote:

So sorry - I thought that checking with the topology checker was the best method to control features.

the topology checker (that despite the name can also check for geometry issues) is great, as a simple way foe users to choose what they want to check, it does not fix anything... so is bit limited

the geometry checker (that despite the name can also check for topolgy issues) gives a lot of options, can fix errors... but honestly is not a great ux

the two above usually yeld slightly different results

anyway, if you want to fix geometries without worrying about parameters, etc... just use postgis st_makevalid (st_IsValidReason if you want to know what error is) or its QGIS incarnation.

closing?

qgib commented 5 years ago

Author Name: Giovanni Manghi (@gioman)

I'm closing Lene because the real problem is the total inconsistency we have among the tools that can check/fix geometries. This issue should really need to be addressed, not even sure if a ticket would be the right starting point.