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I am looking to automate the create of a fishnet grid over a large area (about the size of Rhode Island) for a mapping study. I want to use hexagonal grid cells, but the kicker is I need each of these hexagonal grids again broken down into their 6 hexants. The center convergent vertex will be a setup location with mapping done out to the extent of each hexant. Sort of like flying the petals from the pistil of a flower.

enter image description here

I don't see custom grid shapes in QGIS. I'm wondering how I can create this grid layout.

My first thought was to lay down hex grids and then do a series of layer copying with systematic offsets and a final merge to get what I need. Or to convert grids to polylines, copy those lines with the bearings I want, and repaste/offset those. But there's got to be other tools or a simpler process out there.

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So, here is my suggestion, if I understood you correctly, proceed as follows,

i.e. it is a technique that can be automated:

Input data are hexagons fig. 1

enter image description here

  1. Vector>Processing geometry>Point extract;
  2. Data Analysis>Toolbar>General Vector>Erase the same geometry - this is important!
  3. Create centroids on the hexagon layer, copy them and paste them into the "Cleared Vertices" layer;
  4. Run Vector>Processing geometry>Triangulation Delaunay on the updated merged point layer "Clear Vertices"....
  5. Run Vector>Geo-processing>Crossing (results layer 4 and hexagon)

And you should get what you ask...fig. 2

enter image description here

Translated with www.DeepL.com/Translator (free version)

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  • Thanks for your response. I can't seem to find "Crossing". Is it called something else? And by "Erase the same geometry", you're referring to "delete duplicate geometries", correct?
    – BenW
    Commented Sep 24, 2020 at 18:08
  • these are translation problems! 1) Maybe Intersection...2) "delete duplicate geometries" - yes, that's right... Commented Sep 24, 2020 at 18:15
  • Great thanks. Also I ran my delaunay triangulation on the de-duped vertices + centroids point layer, but this is the resulting triangles. It seems off. imgur.com/a/aw4bVXl.
    – BenW
    Commented Sep 24, 2020 at 18:18
  • Hmmm. Yep that is what I used. Toolbox->Vector General->Delete Duplicate Geometries. Then pasted the centroids into that points layer. Then ran Delaunay. The results are the imgur screenshot. Reran, same results.
    – BenW
    Commented Sep 24, 2020 at 18:33
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    Yes I used Vector>Research Tools>Create a Grid>Hexagons. I also found upon further inspection that there are some erroneous vertices generated and remaining even after removing duplicate geometry. Once I manually deleted those bad vertices of the process worked. Now to figure out why those erroneous extraneous vertices :-/ Thanks!
    – BenW
    Commented Sep 24, 2020 at 19:56

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