Adding polygons

A polygon consists of a border line and a centroid (point). The ID (and all attributes) of a polygon is bound to the centroid. Therefore you will not be asked to confirm any ID when adding line, but only when adding centroid.


       




       


If you add more centroids with the same ID, Field-Map creates multipolygons from them. Several centroids and several polygons create a multipolygon and are related to a single record in the attribute table.

If there is no centroid, then no polygon will be created in polygonization routine.
  1. Make sure that the line layer is active
  2. Click the Add line button and add a border line of the polygon (see Adding line)



  1. Activate polygon layer
  2. Click the Add centroid button and add a centroid (see Adding point) somewhere inside the future polygon

Do this as many times as you have polygons to add. There are no polygons in the layer at this stage but the layer is now ready for polygonization.



Note: 

You can easily move centroid position by mouse/pen (when pen mapping is allowed). Select the centroid you want to move and drag it to the new position