I read about the planarize function in ArcGIS, which seem to do exactly what I want. Is there a similar feature in QGIS or another free tool?

I have a shapefile with various shapes intersecting each other and I want each intersection to become a node and between every two nodes to have a simple line.

The goal is to easily convert my .shp in .osm and use it with Graphserver. As it is, Graphserver says I don't have edges, and I deduced the above is my problem.

Thanks a lot

2 Answers 2


In GRASS GIS which is topological you can use v.net for this operation. You can access it through the QGIS-GRASS Toolbox.

  • Hi! I had a look about the v.net documentation, I'm not sure about the end result I should get to be able to import this in the graphserver…
    – charlax
    Commented Oct 6, 2011 at 1:44
  • You can then export to a OGR supported format with v.out.ogr.
    – markusN
    Commented Oct 8, 2011 at 23:59
  • Odd the documentation isn't very explicit that it handles intersections. Did you try this and does it work? Commented Sep 17, 2012 at 13:10
  • Not sure this works - see my other answer Commented Dec 10, 2015 at 13:28

In GRASS GIS the v.clean tool can be set to break intersections. The rmsa and rmdupl options to v.clean are useful as well.

Returning to this question for a third time: the snap option to v.clean will snap together features by altering their shape to fix apparent intersections, etc. snap followed by break should thus do a job similar to ArcGIS Planarize.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.