Hi, I found now several buildings/areas, which where constructed with multipolygons, but where only the inner polygons where ignored for rendering. As an example see at: http://www.openstreetmap.org/browse/relation/56430 This is a building with tree inner polygons. As long as the outer-polygone http://www.openstreetmap.org/browse/way/10700238 has tags, the whole building is rendered as one whole area. If I move the tags from the outer-polygone to the multipolygone (for example like done with http://www.openstreetmap.org/browse/relation/6187) it's rendered correct. Is this a mkgmap bug? Or is it possible to fix this with the style file? Thanks, Thorsten -- Thorsten Kukuk, Project Manager/Release Manager SLES SUSE LINUX Products GmbH, Maxfeldstr. 5, D-90409 Nuernberg GF: Markus Rex, HRB 16746 (AG Nuernberg)
Am 21.02.2011 23:13, schrieb Thorsten Kukuk:
Hi,
I found now several buildings/areas, which where constructed with multipolygons, but where only the inner polygons where ignored for rendering Hi Thorsten
It seems to be an error in osm-data. If you have a MP, all taggs on outer way describes the hole polygon. All taggs on MP-relation describes the area between outer and inner polygon. Henning
On Mon, Feb 21, Henning Scholland wrote:
Am 21.02.2011 23:13, schrieb Thorsten Kukuk:
Hi,
I found now several buildings/areas, which where constructed with multipolygons, but where only the inner polygons where ignored for rendering Hi Thorsten
It seems to be an error in osm-data. If you have a MP, all taggs on outer way describes the hole polygon. All taggs on MP-relation describes the area between outer and inner polygon.
I was already afraid of that. Looks like at least in Nuernberg, somebody did this consistently wrong :( But I only wonder that the renderer used for the maps on openstreetmap.org is doing it correct. So it's hard to argue that it is a osm-data bug ... Thorsten -- Thorsten Kukuk, Project Manager/Release Manager SLES SUSE LINUX Products GmbH, Maxfeldstr. 5, D-90409 Nuernberg GF: Markus Rex, HRB 16746 (AG Nuernberg)
Am 22.02.2011 00:03, schrieb Thorsten Kukuk:
On Mon, Feb 21, Henning Scholland wrote:
Am 21.02.2011 23:13, schrieb Thorsten Kukuk:
Hi,
I found now several buildings/areas, which where constructed with multipolygons, but where only the inner polygons where ignored for rendering Hi Thorsten
It seems to be an error in osm-data. If you have a MP, all taggs on outer way describes the hole polygon. All taggs on MP-relation describes the area between outer and inner polygon. I was already afraid of that. Looks like at least in Nuernberg, somebody did this consistently wrong :(
But I only wonder that the renderer used for the maps on openstreetmap.org is doing it correct. So it's hard to argue that it is a osm-data bug ...
Thorsten You can take a look into our wiki ( http://wiki.openstreetmap.org/wiki/DE:Relation:multipolygon )
Henning
On Tue, Feb 22, Henning Scholland wrote:
You can take a look into our wiki ( http://wiki.openstreetmap.org/wiki/DE:Relation:multipolygon )
I know that, thanks! But from 15 Multipolygons I checked now in Nuernberg, only one was correct ... And I only checked a very, very small piece ... Thorsten -- Thorsten Kukuk, Project Manager/Release Manager SLES SUSE LINUX Products GmbH, Maxfeldstr. 5, D-90409 Nuernberg GF: Markus Rex, HRB 16746 (AG Nuernberg)
On Mon, 21 Feb 2011 23:18:24 +0100, Henning Scholland wrote:
It seems to be an error in osm-data. If you have a MP, all taggs on outer way describes the hole polygon. All taggs on MP-relation describes the area between outer and inner polygon.
I don't interpret the Wiki docs in this way. Indeed the most MPs are tagged like this: relation: type=multipolygon outerway: landuse=forest (example) innerway: no-tags (or tags for inner area). The forest is of course only the area between inner and outer. Chris
Chris66 schrieb am 22.02.2011 11:05:
Indeed the most MPs are tagged like this:
relation: type=multipolygon outerway: landuse=forest (example) innerway: no-tags (or tags for inner area).
The forest is of course only the area between inner and outer.
This is one of the accepted taggings for a multipolygon. The other possibility (for the same example) is: relation: type=multipolygon landuse=forest (example) outerway: no-tags (or tags for whole area) innerway: no-tags (or tags for inner area). For a render the only way to decide, which tagging scheme is used by the mapper, is checking the tags in the relation. Is there any tag on the relation beside the "type=multipolygon", then second scheme is obviously used. If there is no other tag on the relation, then the first scheme is used. Everything else should be considered as a data error. Gruss Torsten
Am 22.02.2011 16:55, schrieb Torsten Leistikow:
relation: type=multipolygon outerway: landuse=forest (example) innerway: no-tags (or tags for inner area).
The forest is of course only the area between inner and outer.
This is one of the accepted taggings for a multipolygon.
The other possibility (for the same example) is:
relation: type=multipolygon landuse=forest (example) outerway: no-tags (or tags for whole area) innerway: no-tags (or tags for inner area).
the scope for the outerway-tags is depending on the existence of tags on the relation (beside of type=mp) ? I can't believ this. Wiki: The intended use of multipolygons is this: * Tags describing the multipolygon (e.g., landuse=forest) should go on the relation. The outer way(s) should be left untagged, unless they describe something in their own right. For example, a forest could be delineated by four roads, in which case the four ways would be tagged with the highway tag, but could still be used as "outer" members of the forest relation. * If you have one closed way making up the outer ring and it does not describe something in its own right, you may also put these tags on the outer ring and leave the relation untagged. If you have more than one outer way (see "Advanced Multipolygons" below), then this does not make sense. Therefore it is suggested (for consistency) to always put the multipolygon tags on the relation. Tagging * It is suggested to apply all tags which describe the area to the relation, and not to the ways. In many cases this may result in completely untagged ways. * Implementation for compatibility: o Drawing style is taken from the tagging of the relation itself. o If relation is not tagged, the drawing style of outer ways is used. o If the outer styles mismatch or no style is found it is considered an error. o Inner tagging leads to inner drawing. If inner tagging style equals outer style (an old method) the inner style should be handled as empty. Chris
Chris66 schrieb am 22.02.2011 17:47:
the scope for the outerway-tags is depending on the existence of tags on the relation (beside of type=mp) ?
I can't believ this.
Wiki:
...
* Implementation for compatibility: o Drawing style is taken from the tagging of the relation itself. o If relation is not tagged, the drawing style of outer ways is used. o If the outer styles mismatch or no style is found it is considered an error.
The second bullit describes this requirement. Basically we are dealing with an "old" and a "new" tagging scheme. And the only way to differentiate is looking at the tags of the relation. It would have been nicer, if the "new" implementation would use type=advanced_multipolygon for distinction. But sadly this is not the way, the OSM world is working. Gruss Torsten
On Tue, Feb 22, Torsten Leistikow wrote:
For a render the only way to decide, which tagging scheme is used by the mapper, is checking the tags in the relation. Is there any tag on the relation beside the "type=multipolygon", then second scheme is obviously used. If there is no other tag on the relation, then the first scheme is used.
I'm not that firm with releations and mkgmap yet and I cannot remember that I have read something about how this could work. Any reference about docu how this could be implemented in a mkgmap style? Reason: In Nuerenberg, nearly all multipolygons are using the "old" style and are rendered wrong on a Garmin. While it could be possible to fix the ones in Nuerenberg, it's impossible for me to fx all. Thorsten -- Thorsten Kukuk, Project Manager/Release Manager SLES SUSE LINUX Products GmbH, Maxfeldstr. 5, D-90409 Nuernberg GF: Markus Rex, HRB 16746 (AG Nuernberg)
Hi,
I found now several buildings/areas, which where constructed with multipolygons, but where only the inner polygons where ignored for rendering.
As an example see at: http://www.openstreetmap.org/browse/relation/56430
This is a building with tree inner polygons. As long as the outer-polygone http://www.openstreetmap.org/browse/way/10700238 has tags, the whole building is rendered as one whole area. If I move the tags from the outer-polygone to the multipolygone (for example like done with http://www.openstreetmap.org/browse/relation/6187) it's rendered correct.
Is this a mkgmap bug? Or is it possible to fix this with the style file?
Thanks, Thorsten
Hi to all, mkgmap tag handling of multipolygons is a compromise between the strict rule to tag the mp-relation only and the real OSM world. Assume the following scenario: relation: type=multipolygon way 1: role=outer way 2: role=outer ... way 7: role=inner way 8: role=inner ... 1st case: the mp contains more than the type=multipolygon tag. The multipolygon (space between outer and inner ways) is tagged with the mp tags. The mp tags are removed from the original outer ways. 2nd case: the mp contains only type=multipolygon The multiypolygon is tagged with the intersection of tags of the outer ways. These are removed from the original outer ways. What does that mean for your mp http://www.openstreetmap.org/browse/relation/56430? In the original version the mp was tagged with name=Germanisches Nationalmuseum, so the multipolygon contained the name tag only. The name tag was removed in the outer way. So in the end the outer way was rendered without holes and without the name. The mp (with holes) was not rendered because there is no rule for a polygon with a name tag only. In the current version 3 the mp (outer way with holes) is tagged with building=yes name=Germanisches Nationalmuseum tourism=museum wikipedia:de=Germanisches_Nationalmuseum. These tags are removed from the outer way 10700238 so it is left with source=yahoo Probably there is no rule for the source tag so the "holeless" outer way is not rendered. The tags of the inner ways are not changed. WanMil
participants (5)
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Chris66 -
Henning Scholland -
Thorsten Kukuk -
Torsten Leistikow -
WanMil