Re: [Qgis-user] most efficient way to digitize polygons
Hello Byron, There are a couple of solutions I normally use in those situations. But before that take a look at the snapping documentation: https://docs.qgis.org/3.22/en/docs/user_manual/working_with_vector/editing_geometry_attributes.html#topological-editing Also check the digitising on the layer properties to constantly validation: https://docs.qgis.org/3.22/en/docs/user_manual/working_with_vector/vector_properties.html#digitizingmenu Other than that, I normally prefer to create one by polygon and then split it with the split geometries tool, but make sure to enable topological editing. The other option is using the avoid overlapping option, that way you can do just a few click in the inside an neighbours polygons and qgis will draw the boundary for yoy. Third option, use the tracing tool. Best regards, Alexandre Neto Users support www.qcooperative.net A quinta, 16/06/2022, 17:43, Nicolas Cadieux via Qgis-user < qgis-user@lists.osgeo.org> escreveu: > Hi, > > Depending on what you are doing and what kind of results you are looking > for, could you simply use "Polygonize" and then clean those results. If > your map are in RGB only, you could do a raster classification analysis > before hand. Line would follow pixels at first but those could be fixed > using various vector tools. > > Just a thought! > > Nicolas > On 2022-06-16 11:26 a.m., Firstname Lastname via Qgis-user wrote: > > i am a qgis newby and i am beginning a large project that involves > digitizing several geology maps. i am trying to determine the best way to > manage the digitizing and avoid extra work. > my question to the group is: If i have several coloured polygons that are > adjacent to each other, is there an efficient way to digitize one polygon > and then use one edge of that polygon for the adjacent polygon so that i > dont have to redigitize the same edge twice and so that i will have > precisely overrlapping polys with no gaps? should i digitize one polygon, > export and rename it? can i digitize one have of the next polygon and > somehow merge it with the now re-imported polygon? > is there a more efficient way to do this? > > many thanks > > -- > Byron Veilleux, MSc. P.Geo > Conjugate Geologic Services Limited > Calgary, Alberta Canada > by...@conjugategeo.com > > > ___ > Qgis-user mailing listqgis-u...@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > > -- > Nicolas Cadieuxhttps://gitlab.com/njacadieux > > ___ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] most efficient way to digitize polygons
Hi Byron, I recommend making one large polygon and then using the Split Features tool to cut individual polygons out of the original polygon. Just remember to select the polygon that you want to split before using the tool, and start and finish the split line on the outside of the polygon. This effectively eliminates topological errors between the adjacent polygons. Which means that there will not be any gaps or overlaps between them, since the splitting process will generate duplicate points in each polygon for every mouse click along the split path. The only disadvantage is that you will have to manually go back and fill in the attributes for each polygon. Know that the new polygon that is split from the original will inherit the attributes of the original. If you need to adjust boundaries later, you should use the Snapping Toolbar, specifically enable Snapping and enable Topological Editing. When polygons share points, if you move a point it will move all polygons that share that point. -Thayer On Thursday, June 16, 2022 at 03:00:38 PM EDT, qgis-user-requ...@lists.osgeo.org wrote: Date: Thu, 16 Jun 2022 09:26:32 -0600 From: Firstname Lastname To: Qgis-user@lists.osgeo.org Subject: [Qgis-user] most efficient way to digitize polygons Message-ID: Content-Type: text/plain; charset="utf-8" i am a qgis newby and i am beginning a large project that involves digitizing several geology maps. i am trying to determine the best way to manage the digitizing and avoid extra work. my question to the group is: If i have several coloured polygons that are adjacent to each other, is there an efficient way to digitize one polygon and then use one edge of that polygon for the adjacent polygon so that i dont have to redigitize the same edge twice and so that i will have precisely overrlapping polys with no gaps? should i digitize one polygon, export and rename it? can i digitize one have of the next polygon and somehow merge it with the now re-imported polygon? is there a more efficient way to do this? many thanks -- Byron Veilleux, MSc. P.Geo Conjugate Geologic Services Limited Calgary, Alberta Canada by...@conjugategeo.com -- next part -- An HTML attachment was scrubbed... URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20220616/f37e9e02/attachment-0001.htm> ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] most efficient way to digitize polygons
Hi, Depending on what you are doing and what kind of results you are looking for, could you simply use "Polygonize" and then clean those results. If your map are in RGB only, you could do a raster classification analysis before hand. Line would follow pixels at first but those could be fixed using various vector tools. Just a thought! Nicolas On 2022-06-16 11:26 a.m., Firstname Lastname via Qgis-user wrote: i am a qgis newby and i am beginning a large project that involves digitizing several geology maps. i am trying to determine the best way to manage the digitizing and avoid extra work. my question to the group is: If i have several coloured polygons that are adjacent to each other, is there an efficient way to digitize one polygon and then use one edge of that polygon for the adjacent polygon so that i dont have to redigitize the same edge twice and so that i will have precisely overrlapping polys with no gaps? should i digitize one polygon, export and rename it? can i digitize one have of the next polygon and somehow merge it with the now re-imported polygon? is there a more efficient way to do this? many thanks -- Byron Veilleux, MSc. P.Geo Conjugate Geologic Services Limited Calgary, Alberta Canada by...@conjugategeo.com ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info:https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe:https://lists.osgeo.org/mailman/listinfo/qgis-user -- Nicolas Cadieux https://gitlab.com/njacadieux ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] most efficient way to digitize polygons
Byron and list, On Thu, Jun 16, 2022 at 8:26 AM Firstname Lastname via Qgis-user < qgis-user@lists.osgeo.org> wrote: > i am a qgis newby and i am beginning a large project that involves > digitizing several geology maps. i am trying to determine the best way to > manage the digitizing and avoid extra work. > my question to the group is: If i have several coloured polygons that are > adjacent to each other, is there an efficient way to digitize one polygon > and then use one edge of that polygon for the adjacent polygon so that i > dont have to redigitize the same edge twice and so that i will have > precisely overrlapping polys with no gaps? should i digitize one polygon, > export and rename it? can i digitize one have of the next polygon and > somehow merge it with the now re-imported polygon? > is there a more efficient way to do this? > > You may wish to read one or more of the available tutorials on the topic of digitizing in QGIS. For example, this one: https://www.qgistutorials.com/en/docs/3/digitizing_basics.html where you would pay particular attention to steps 22 through 26 where snapping new polygons to existing ones is demonstrated. -- Chris Hermansen · clhermansen "at" gmail "dot" com C'est ma façon de parler. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] most efficient way to digitize polygons
i am a qgis newby and i am beginning a large project that involves digitizing several geology maps. i am trying to determine the best way to manage the digitizing and avoid extra work. my question to the group is: If i have several coloured polygons that are adjacent to each other, is there an efficient way to digitize one polygon and then use one edge of that polygon for the adjacent polygon so that i dont have to redigitize the same edge twice and so that i will have precisely overrlapping polys with no gaps? should i digitize one polygon, export and rename it? can i digitize one have of the next polygon and somehow merge it with the now re-imported polygon? is there a more efficient way to do this? many thanks -- Byron Veilleux, MSc. P.Geo Conjugate Geologic Services Limited Calgary, Alberta Canada by...@conjugategeo.com ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
