As a land surveyor, I often bring cad data into a GIS and create polygon representing parcels.  Traditional tools I have for cleaning topology are inappropriate so I am looking for something different - even if it means teaming up with someone to build additional extensions.  (I scanned the list of existing extensions and some pieces are already there).  My idea is to fix minor topology errors by constraining key geometric elements. That is, straight polylines and circular arcs which share a common centre point.  A key requirement is support for true circular curves.  I could keep the data in SQL Server but prefer a GUI for a better user experience.  As I am not familiar with QGIS, I am looking for some indication if the data structure used by QGIS can support this.
123799
I am trying to make a floor plan for my office, have managed to make all of the rectangular components (e.g. the rooms) however some of the desk layouts are circular and I haven't been able to work out how to make exact and measured circles. They need to have a radius of 1.45m.
22957
How can I create a 3D shapefile containing line features or point features? I have to extract the elevations from a DEM and then export a shapefile containing 3D features. I'm currently working with QGIS 2.8.4
24546
I am newcomer to Blender and modeling in general. Currently, I am working on modeling a cat. I am noticing at times loops are missing from the polygons.  Here is an example:     Is there any easy way to fix/add a line for consistency and what is the best approach to avoid this when modeling in general for consistent topology?
6579
I have a polygon Shapefile, which I need to generalize. How can I generalize the poligons and ensure that there are no topological errors like "slivers".   I already tried:   Vector -> Geometry Tools  -> polygones to lines Vector -> Geometry Tools  -> simplfy geometries ... here I can already see on the screen, that I am producing overlaps and gaps nevertheless now I try Vector -> Geometry Tools  -> lines to polgones   and here the program show an error and crashes
58860
Not that I am in any immediate need of a right answer here, but I've lately seen some efforts to introduce the concept of "(distributed) version control systems" for geographic data. Some examples (that I know of) are the three whitepapers from OpenGeo (,  &amp; ) and the " (geosyncronization)" project by Norwegian GIS Software vendors and the Norwegian Mapping Agency. I've also found , which mentions GeoGit (by OpenGeo), and  about version control in ArcGIS.  Being a developer I know (at least enough to be able to use them) how version control systems for source code (like SVN and Git) works, and my background in geomatics tells me that there are some unique challenges with geographical data that makes the approach not completely similar to the way source code (which is basically text) are handled.  What are the challenges when dealing with (d)VCS'es for geographical data, how would you solve them, do we need them and are there other attempts to solve these issues than the ones I have mentioned?  I know that the OpenGeo whitepapers will answer some of my questions, but what I'm really is after is a more "pedagogical" answer, in the style of "tell me like I'm a 10-year-old", so that I can refer people to a great explanation of the challenges and solutions that geographical data brings to the mix.  I hope that someone with some insight will take time to provide some thoughts on the matter, as I said I'm not currently looking to solve a particular problem, but this topic is one that interests me.
51188
I want to connect all points in a point feature with every possible line segment using QGIS. For example, how a pentagon has five points with ten line segments connecting them all to form a pentagram inside. Alternatively phrased: How do I make spokes when all the points are hubs? I don't care about the order, I just want every connection between two points as one line each. Is there a tool or script that can do this in QGIS? This topic () is the closest to what I want but the plugins are no longer supported.
66380
I have a few hundred shapes (polygons and multipolygons) each consisting of tens of thousands of points that I am trying to get into SQL 2008.  Unfortunately, the shapes I have tried to import are "right-handed" (the perimeter of each one is drawn clockwise around the points it contains). SQL server assumes "left-handed" shapes (anti-clockwise around the interior), at least for geography types. This means that SQL assumes that I'm trying to select the entire earth except for my shape. Some people describe this as "inside-out" shapes.  From , which frustratingly doesn't say which ring orientation one is to use:     If we use the geography data type to store the spatial instance, we must specify the orientation of the ring and accurately describe the location of the instance.   If you use the wrong ring orientation in SQL 2008, it crashes with the following error (emphasis mine):     A .NET Framework error occurred during execution of user-defined routine or aggregate "geography":    Microsoft.SqlServer.Types.GLArgumentException: 24205: The specified input does not represent a valid geography instance because it exceeds a single hemisphere. Each geography instance must fit inside a single hemisphere. A common reason for this error is that a polygon has the wrong ring orientation.   Importing the shapes as geometry instead of geography works fine, but I'd like to use geography if I can.  In SQL 2012, it appears  to fix this problem, but I am tied to 2008.  How should I convert the shapes?
70040
I want to  create a small web application to visualize election results on a per poll site basis for my city. The result is going to be very similar to what has been done for Berlin . Hopefully this helps in understanding what I'm going for.  The election raw data on the scale I need is published and I know how to visualize this on the grounds of a shapefile with separate polygons lining out the election districts. My problem is - as you could probably guess - that something like this doesn't already exist.  What actually is published though, is a PDF file lining out the borders of the districts I'm interested in:   I'm not keen on redrawing the linework myself, so I'm looking for a way to make a shapefile out of this. Luckily, the PDf includes the linework as separate vector objects, I extracted these into a SVG file:   I already tried converting the SVG to a DXF and importing it into qgis 2.0.1. This actually works, but (as expected) places the vectors in the atlantic ocean and I can't find a way to edit it and fix this.  What can I do now to georeference these vectors with open source tools and finally produce a shapefile?
119616
I work with QGIS 2.10.1 on Windows 7 (x64). I have dissolved polygons from an attribute value and the polygons geometries being not perfectly joined together, I get some 'garbage' nodes I need to delete. I have tried to edit the layer and using nodes tool, selecting and deleting the nodes, but it seems impossible to do (nodes are not deleted at all!). Any idea on how to process this kind of clean-up?  EDIT : you can  for testing.
120837
I want to know if there is a plugin in QGIS, which will allow me to draw the outline a point cloud. I know there Points2One the plugin, but it makes an outline with all points, even with the data found in the middle of the point cloud.  I give you an example ;  x       y       ID      order 3.3     43.2625 353293  1 3.13334 43.3458 353293  2 3.21667 43.3458 353293  3 2.88334 43.4292 353293  4 2.96667 43.4292 353293  5 3.05    43.4292 353293  6 3.13334 43.4292 353293  7 2.71667 43.5125 353293  8 2.8     43.5125 353293  9 2.88334 43.5125 353293  10 2.96667 43.5125 353293  11 3.05    43.5125 353293  12 3.13334 43.5125 353293  13 2.88334 43.5958 353293  14 2.96667 43.5958 353293  15 3.05    43.5958 353293  16 3.13334 43.5958 353293  17 2.96667 43.6792 353293  18 3.05    43.6792 353293  19 3.13334 43.6792 353293  20 3.21667 43.6792 353293  21 3.05    43.7625 353293  22 3.13334 43.7625 353293  23 3.21667 43.7625 353293  24 3.13334 43.8458 353293  25 3.21667 43.8458 353293  26   With the tool suggested by @ArMoraer I can only draw a polygon with the outer points that are more extreme. The polygon has touched just 5 points (see map of Convex hull below) but normally it should pass on 20 points (all points of the contour).     Each point has a pixel, actually the outline should not touch the points but it must pass through the outer limit of these pixels. In the end I want to have an outline like this map (see map below : desired contour)
48013
I've tried without much success to add a curved line feature to the ArcGIS JavaScript map.    I created a polygon with a curved edge in ArcMap:   However, when I load this same feature in the web API, it becomes segmented:   The problem started when I tried to create a curved feature from the JavaScript API itself, which only seems to allow full circle features (not circular arcs).  This makes me think that curves are still unsupported in the JavaScript API. Do you know any way around this? Do you have any other ideas on alternatives I can use to create and correctly view curved features?
93928
I have a shapefile with a single Polygon feature. This feature has a "ring not closed" geometry error (seen here in QGIS):   I tried using buffering and the GRASS v.clean command as suggested in other answers, but no luck. I also can't find the gap by inspecting the feature visually (it looks perfect).  I need a valid geometry here. Ideally, I'd like to have a Python/command line solution. Any way of doing this manually in QGIS/ArcGIS would also be great.  UPDATE: this shapefile can be downloaded .
1829
I am new at using QGIS. How can I simply split features in QGIS? The manual tells to simply draw a line through the polygon you want to split. But it doesn't work. The line disappears when finishing it. When I select the polygon and then split it, it sometimes works and sometimes doesn't (an info appears after which it does not split the feature). Does anybody have an idea why the tool does not work properly?
114197
I receive a topology error notification when intersecting a point dataset (with ~5 million points), with a polygon dataset created by buffering those points by a half mile. The goal is to create a table containing the intersection of the two datasets such that I have a list of all points within that half mile radius of each starting point. I can generate effectively identical results using either an intersection or a spatial join. My prototype of this process works fine when I work on a small subset of each dataset. When I scale up to the full dataset, the intersect operation fails with a topology error, and the spatial join fails with an out of memory error (which is plausible given the dataset size, and memory addressing limitations of a 32bit application). Much of the time I do these operations in PostGIS (successfully and easily), but on this project I'm constrained to working in ArcMap, with the assumption that my users will have only the ArcView (Basic) level of licensing. I've also done these operations in spatiallite. I'd really rather not have to pull in OGR2OGR to move the datasets to spatiallite for the processing, but can if I must. Machine specs: Intel Core2 Quad (Q9550), Windows 7 (64bit), 8GB of ram, plenty of hard drive space
47369
How do I create a centerline (vector data) from two parallel polylines (vector data) in QGIS? For example, if the distances between two parallel lines are 14m, then I want to create a centerline at 7m from both lines.
53137
I am trying to create polygons from a line layer of lots and concessions (large blocks of land in rural areas).   The lines are mainly grid style as they intersect mostly at right angles.   I need to create polygons from these lines.   I tried it in QGIS and it did not work.   Any suggestions other than digitizing?   I'm using ArcEditor 10.
57740
I am searching for a downloadable database of administrative boundary shapes, best would be worldwide data.  I have found  but it seems a bit outdated, also the  seems interesting but I haven't found any exports based on this definition.  The detail level of the shapes is not that important as it would be used to let a user select the city/region (if not in a city or no data for that city available). A hierachical representation like Country > Region > City would be great.