I am trying to create smooth looking polygons by gridded points in QGIS (2.18.16), with a fading effect towards the boundary of the polygons (halftone effect).

By using the 'fillGrid' function from Rob J, I managed to create gridded point pattern in Geometry Generator.

Now I would like to add a size decrease of the point marker towards the boundary of each polygon starting from a maximum size (e.g. 2 mm) to a minimum size (0 mm). What is the best way to do this? Maybe there is a faster way by using the standard 'point pattern' option as symbol layer type?

Example image demonstrates the desired effect inside each polygon. Halftone effect inside polygon

  • Could you please edit your question to include some screenshots of what you have? :) – Joseph May 9 '18 at 9:25
  • 1
    Hope this helps! The code is exactly as in the link, let me know if I should insert this code here too :) – Tjavajive May 9 '18 at 9:32
  • I suggest adding a field to the points layer that calculates the distance between that point and the centroid of the polygon. Then base the size of the point on that field. – csk May 9 '18 at 19:19
  • My previous comment was based on the points being in a separate layer. I don't think you can do a distance calculation using a generated geometry. – csk May 9 '18 at 19:35
  • Thanks @csk for the option. I might consider this for now, but I would still prefer to know whether it is possible using geometry generator. – Tjavajive May 15 '18 at 12:46

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