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<div dir="ltr" data-setdir="false">Hi Bernd,</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">That sounds like you may have a topology problem, like self intersection.<br></div><div dir="ltr" data-setdir="false">Have you tried 'Vector Geometry': 'Fix Geometries' in the Processing Toolbox?</div><div dir="ltr" data-setdir="false">In the same place there is also a 'Check validity' tool, which would find the problems for you and then you could fix them manually. The tool gives you options for different standards of validity.</div><div dir="ltr" data-setdir="false">Another possibility is that you have mixed geometry types. You might be able to fix that with GRASS: v.type or Processing:'Vector geometry': 'Convert geometry type'</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">In PostGIS you would check if the imported geometry column is </div><div dir="ltr" data-setdir="false">SELECT id FROM dwg_table WHERE NOT <span><span style="color: rgb(0, 0, 0); font-family: Helvetica Neue, Helvetica, Arial, sans-serif;">ST_IsSimple(geom)</span></span></div><div dir="ltr" data-setdir="false">or: </div><div dir="ltr" data-setdir="false">SELECT ST_GeometryType(geom) FROM dwg_table GROUP BY <span><span style="color: rgb(0, 0, 0); font-family: Helvetica Neue, Helvetica, Arial, sans-serif;">ST_GeometryType(geom)</span></span>. </div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">-Thayer</div><div><br></div><div><br></div>
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On Monday, December 7, 2020, 01:58:04 PM EST, qgis-user-request@lists.osgeo.org <qgis-user-request@lists.osgeo.org> wrote:
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<div><br></div><div><div dir="ltr">Date: Mon, 7 Dec 2020 19:57:19 +0100<br></div><div dir="ltr">From: Bernd Vogelgesang <<a href="mailto:bernd.vogelgesang@gmx.de" rel="nofollow" target="_blank">bernd.vogelgesang@gmx.de</a>><br></div><div dir="ltr">To: qgis-user <<a href="mailto:qgis-user@lists.osgeo.org" rel="nofollow" target="_blank">qgis-user@lists.osgeo.org</a>><br></div><div dir="ltr">Subject: [Qgis-user] Problem splitting polygons with line layer<br></div><div dir="ltr">Message-ID: <<a href="mailto:82a7c751-29c2-9906-25e6-9038979865ef@gmx.de" rel="nofollow" target="_blank">82a7c751-29c2-9906-25e6-9038979865ef@gmx.de</a>><br></div><div dir="ltr">Content-Type: text/plain; charset="utf-8"; Format="flowed"<br></div><div dir="ltr"><br></div><div dir="ltr">Hi,<br></div><div dir="ltr"><br></div><div dir="ltr">I need to split a polygon with a line layer (representing parcel<br></div><div dir="ltr">boundaries ).<br></div><div dir="ltr"><br></div><div dir="ltr">Using "Split with lines", the process always stops at 12% and there is<br></div><div dir="ltr">no progress visible. The lines are imported from a CAD dwg as a<br></div><div dir="ltr">CompoundCurveZ (never had to do with this before)<br></div><div dir="ltr"><br></div><div dir="ltr">My goal is to "cut" the polygon, so I retrieve parcels of a specific<br></div><div dir="ltr">area again.<br></div><div dir="ltr"><br></div><div dir="ltr">With other line layers from this dwg ist no problem spliting the<br></div><div dir="ltr">polygon, only the parcel boundaries won't work.<br></div><div dir="ltr"><br></div><div dir="ltr">Does anybody have an idea what could be the cause of this problem, what<br></div><div dir="ltr">I other tools I could try or if I have to proprocess the lines<br></div><div dir="ltr">beforehand with other tools?<br></div><div dir="ltr"><br></div><div dir="ltr">Hoping for enlightment (and having a deadline tomorrow)<br></div><div dir="ltr"><br></div><div dir="ltr">Bernd<br></div><div dir="ltr"><br></div></div>
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