I am using the QGIS (2.8.1) Voronoi Polygons Algorithm on a point shapefile. See image below, the red triangles are the points I am using. The resulting polygons miss a part (around HP87).

Any ideas why?

Resulting voronoi polygons

Here is some example data (EPSG:2154) that reproduces the error (excluding point A):

  • 3
    I see this weird phenomena in QGIS 2.18.16, with QGIS geoalgorithm and v.voronoi. (Potentially related to an unanswered question ). They seem to ignore outmost point. SAGA Thiessen polygons is unaffected...
    – Kazuhito
    Commented Feb 20, 2018 at 16:23
  • 1
    Can you provide a sample data? Commented Feb 20, 2018 at 16:58
  • @AlexandreNeto A sample data was added. Will you give it a go? (I am testing it with various buffer region. It behaves strange when the buffer exceeds approx. 9 ~10.)
    – Kazuhito
    Commented Feb 22, 2018 at 14:47
  • 1
    There were several bugs in the QGIS Voronoi code. Should be fixed in QGIS 3.2.2. Could you try it? Commented Aug 25, 2018 at 19:29

1 Answer 1


I've tested in QGIS with 2 different tools. The grass v.voronoi and the internal voronoi.

From QGIS the v.voronoi doesn't work properly (it lacks polygons in my case): enter image description here

Howerver the voronoi tool seems to work properly: enter image description here

Here is my config: enter image description here

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