Improper result from the “clipper”,

A good idea, as u do this often ....;), is to make a little workbench that checks topology of features before u do spatial processing.

 

 

Topology check would involve spatialrelating and output different relations: overlaps, crosses etc.

 

This u need to do per set and also between the sets.

 

 

Gio

Hi Jamal,

 

 

U can indeed use this topology builder, though i ment creating topology checks using a spatialrelator.

 

After the filter enter the boudnary to area input of topologybuilder.

 

Use geometrycoercer on the landuse, coerce to line. Enter this to line input of topologybuilder.

 

 

If us now set inspectors on the 3 outputs, you can see where it goes wrong.

 

In this case the boundary is not matched to the landuse.

 

U can see this by teh location where the topologybuilder puts nodes.

 

Missing nodes on "key" position tells you more or less that a clipper will not be able to clip there.

 

(thats why if u scale the boundary up, it does clip without error)

 

 

 

You can also use a dissolver on the landuse (no grouping) and then use clipper:

 

 

 

You now have the roads, but with bad objects at the edge.

 

 

Compare it with the topology and you can see that bad parts mis nodes at key positions, have crossing boudaryies etc. :