QGIS » QGIS Application

Forgot to expand on the qgis-import_vs_actual-osm.png; the imported lines are displayed using red squares along path, overlaid on top of OSM tiles. In total, three ways are imported, and a bunch of visible tracks / paths / etc. ways are clearly missing.

QGIS currently uses this kind of query for download:

http://overpass-api.de/api/interpreter?data=(node(14.3833,104.638,14.4167,104.706);<;out;

What it does is that it returns all nodes in the bounding box + ways and relations referring to those nodes. Now, the ways containing nodes that are outside of the bounding box cannot be reconstructed properly and they are silently ignored.

What would be the best way to deal with this situation? We can query also nodes outside of the bounding box if used by some ways like this:

http://overpass-api.de/api/interpreter?data=(node(14.3833,104.638,14.4167,104.706);way(bn);node(w););out;

Upon reconstruction, this may give a bit surprising result, because often big ways (that span through big area, e.g. border line) may completely dominate the actual area of interest. Probably we should have an option to clip the resulting layer to originally asked extent.

Also, I guess we need to check whether the .osm file being loaded is complete (e.g. no missing nodes for ways) and if not, refuse opening such file.

Thoughts?

I don't think that users should be forced to download always full features and relations because they can be quite big. And if user has received some OSM data from external source it would be unfriendly to prevent opening the dataset totally just because some features are not complete.

OpenJUMP OSM reader is writing into attributes if features has been resolved totally. That might be worth thinking.
http://sourceforge.net/apps/mediawiki/jump-pilot/index.php?title=Working_with_OpenStreetMap_data

Martin, there are ways that are confined within the bounding box (see the yellow tertiary highway, some small stair ways, and tracks) yet are not downloaded / exported to lines. Wondering whether there are two issues here. One with how to deal with partial ways, and the other with ways well within bounding box not being retrieved or exported to polylines.

I have found this same issue and the workaround is to download the .osm files using the export button on www.openstreetmap.org

The tertiary road is correctly downloaded, I can see it in the ways table (id=204549674, http://www.openstreetmap.org/way/204549674).
The problem is that it itsn't put into the polylines spatialite layer.

Martin, your suggestion causes recursions which, for areas bigger then this example, will make the query fail (Overpass will kill it).

http://overpass-api.de/api/interpreter?data=(node(14.3833,104.638,14.4167,104.706);way(bn);node(w););out;

Maybe related to #10790