QGIS – Creating Polygon from Hole in Polygon

holespolygonpolygon-creationqgisring

I work with this polygon and try to find a way to create a new polygon from the empty gap (not distinguish it) in the middle of the polygon.

I succeed to do it with the "Difference" tool but used with another layer on the polygon and then using the difference tool.

I can also digitize the shape of the hole and create a new layer I seeking an automated way to do it and not doing in manually.

I read:

Is it possible to do it with a direct tool in QGIS 2.18.1, without the aid of another layer?

example

Best Answer

I recommend Digitizing Tools plugin.

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Once installed, you will find a new toolbar. The eighth from the left of this toolbar, there is an icon called Fill ring with a new feature (interactive).

For you to fill all rings at once;

  1. Switch to Fill all rings in selected polygons with new feature mode by clicking on a small triangle (right-hand-side).
  2. Start editing mode and select polygons you want to work on (you can select all polygons).
  3. Click on the tool icon.
  4. A small dialog box will appear and asks you to give a new attribute value. This value will be given all fillings, so that it helps you to identify these new features in the attribute table. Hit [OK] to close.
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