Hi Apollinaris, On Tue, Feb 02, 2010 at 02:35:26AM -0800, Apollinaris Schoell wrote:
ideally splitter should keep the whole relation in each tile which contains nodes/ways of this relation. mkgmap can fail on incomplete relations
Currently, splitter seems to preserve the relation, but it may discard relation members or nodes constituting ways in the relation. I investigated http://www.openstreetmap.org/browse/relation/311221 that mkgmap was complaining about. In the tile file, the multipolygon is defined as at http://www.openstreetmap.org/browse/relation/311221 but the Palosaari island http://www.openstreetmap.org/browse/way/43829168 is not defined in the tile file, because it is too far from the tile boundaries (tile:lat<62.226562, island:lat>62.274). Because mkgmap ignores unresolvable relation member references, it will treat the multipolygon as if it only had the lake in role=outer and no other members. The lake polygon is intact in the tile file: <way id='4717407'> <nd ref='30037150'/> <nd ref='335160092'/> ... <tag k='name' v='Palokkajärvi'/> <tag k='natural' v='water'/> </way> This matches what I got when downloading and saving in JOSM the following point at the coastline: http://www.openstreetmap.org/?lat=62.2807084&lon=25.7284731&zoom=18 Last, I grepped the node ids from the tile file. Only 46 of the 182 nodes are defined in the tile file. The northmost included point is this one: <node id='30037138' lat='62.2692188' lon='25.7421118'/> Interestingly, the entire lake falls outside the tile boundaries. The tile is 59.414063,19.116211 to 62.226562,31.596680 but the south tip of the lake is lat=62.2605. I can suggest two solutions to this issue: * splitter should flag and preserve all nodes that belong to ways that belong to multipolygon relations (I would not care about route relations, for example) * mkgmap should discard multipolygon relations that consist of only one way Best regards, Marko
On Tue, Feb 2, 2010 at 1:28 AM, Marko Mäkelä <marko.makela@iki.fi> wrote:
Hi WanMil,
I am considering to download a bigger map extract and cutting it to rectangular tiles with splitter, so that I can work around the issues with Geofabrik boundaries.
Do you have an idea how to fix the problems at splitter tile boundaries, such as these when splitting at lat=62.226562:
http://www.openstreetmap.org/browse/relation/302897 http://www.openstreetmap.org/browse/relation/306274 http://www.openstreetmap.org/browse/relation/311221
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