To carry out intersections, at least one involved network object type has to be two-dimensional. To obtain this, a buffer can be created around a network object.
A buffer assigns an area to a point object, line object or a polygon. The resulting area is intersected along with the actual network object. An object point thus becomes a two-dimensional object when calculating the intersection.
The buffer is not defined based on the polygon centroid, but on each point of the polygon. This means, that the buffer is also placed around the polygon like a belt.
Source or target objects are first inflated by the set buffer size(s). The proportion is then calculated by which the target buffer overlaps the source buffer(s). Together with the attribute value of the source object, this share then enters the attribute value of the target object.
The buffer operation (obj, radius) assigns the area (buffer) resulting from all points that have a distance of ≤ radius to a point of obj to the particular object. Radius = 0 results in the obj itself. In the case of polygon objects, polygons plus their buffers are intersected.
