Difference

The difference operation computes the spatial difference between the geometries of two layers. The geometries of the input layer that have the difference with the geometries of the overlay layer will be cut and included in an output layer. The difference result is also called the relative complement of geometry B relative to geometry A.


Click on PROCESSING → VECTOR PROCESSING → DIFFERENCE.

On the In tab select the layer and define the input. Choose the columns to be transferred to the output layer and click on the right arrow button.


Select the input layer and the difference layer (overlay layer) from the lists. A list of attributes will be shown in the left list below.

Check the Only selected objects box if you wish to process only the objects that are selected in the map display.

Select the attributes to be included in the output layer and click on the right arrow button to move them to the right list.

Select one type of repository by clicking on the button to save the output layer as a file or on the button to save it in the database.

Move to Output object type tab and select between single or multiple objects.


Below left you see the input layer and on the right the overlay layer to differentiate.



Below is the output layer resulting from the difference spacial operation.