[Qgis-user] Problem with "non valid geometry"

[Philip Barlow]

Hi Boris,

You could try the old buffer by zero trick if its self-intersections you are having a problem with.

Phil
From: Qgis-user [mailto:qgis-user-bounces at lists.osgeo.org] On Behalf Of Kirk Schmidt
Sent: 09 May 2018 13:45
To: qgis-user at lists.osgeo.org
Subject: Re: [Qgis-user] Problem with "non valid geometry"


Hi Boris:

You can use the grass modules under processing toolbox>Grass GIS 7 commands>Vector>v.build.check or v.clean to isolate the problem. Typically it is a polygons with and intersecting sliver that creates the problem.

Kirk

On 5/9/2018 9:35 AM, boris diaz wrote:
Hi there, I´m trying to cut a raster with a polygon mask in qgis 2.18
The validation tool produces a draw with the message "valid output", but the topology tool finds a "non valid geometry" in the id objetc 0. The shape has only one object, an irregular polygon representing a watershed. SO the error shows the entire watershed.
Anyone can help me finding the real error and how can i repair it?
Thanks. Boris
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Boris G. DIAZ - Mg.Sci.Ing. Forestal
Área Recursos Hídricos - INTA EEA Santa Cruz
Unidad Académica Río Gallegos (UNPA)
https://www.facebook.com/aguapatagonia/<http://santacruzhidro.blogspot.com.ar/>
http://santacruzhidro.blogspot.com.ar/
www.researchgate.net<http://www.researchgate.net>
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Kirk Schmidt, MScF, BScF, RPF

General Manager

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