Subdivide Geometries

This operation subdivides geographically large areas such as the state of Amazonas, ensuring that they do not have more than a given number of vertices. The idea is to speed up spatial operations like Contains, Intersection, etc.

Here is an example of some large objects (red lines) and the number of vertices and memory used to hold them.

Subdivided Polygonsvertives 

Compare the original  number of vertices/memory with the  partial  list of polygons generated by the Subdivision (red line) of 'Am' state.  In this example the number of vertices is up to 255 and the memory is much smaller.

verticessub

See also the  Advanced Dissolve operation in the vector processing menu. It may be useful to dissolve the artificial polygons of each state after some space operation.

It is accessed through:

    Processing > Vector Processing > Subdivide Geometries...

  1. Input Data:   select the input layer with large geometries
  2. Max Coordinates : define the max number of vertices  of each geometry  - default is 1000.
  3. Output: inform where to save the result by clicking on:
  4. Click Applyto perform the operation or Cancel Operation to Cancel
  5. Click on Close  to close the interface and allowing to insert the new layer at the project.