Re: [OSM-talk] [Talk-us] NHD Dataset
Hi all, Mapnik already support this,see: http://openstreetmap.org/browse/relation/24849/ But production osmarender not yet: http://openstreetmap.org/?lat=49.6758lon=15.9996zoom=12layers=0B00FTF What's the problem with osmarender patch? The problem is that neither bobkare nor I really can review the patch. It is attached to http://trac.openstreetmap.org/ticket/1435. If Frederik or someone else with enough time and knowledge of perl and osmarender tells me looks good to me I'll apply it. If somebody else with svn access wants to apply it without review fine with me too. I just don't want to break everthing by applying a patch I don't understand. Patrick Petschge Kilian ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] [Talk-us] NHD Dataset
On Mon, Feb 16, 2009 at 8:20 PM, Frederik Ramm frede...@remote.org wrote: There really is not much other choice, as areas grow larger and the old idea of simply drawing touching polygons relies on a rendering style without a casing around the polygon. Yep, please avoid making one polygon by using two or more touching polygons. The cyclemap already renders forests with translucent fill and an edge symbolizer, which nicely shows up this problem. Frederik's advanced multipolygon concept is the best approach. Cheers, Andy ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] [Talk-us] NHD Dataset
On Mon, Feb 16, 2009 at 12:55:51PM -0600, Ian Dees wrote: It looks like the solution is to use Advanced Multipolygons: http://wiki.openstreetmap.org/wiki/Talk:Relation:multipolygon#Advanced_multipolygons Does anyone want to start writing an algorithm to nicely slice up polygons into small enough chunks? So, to be clear, what this looks like to me is that for any polygon, you can take the 'one long way' that would previously have outlined it, and instead of having that 'one long way', you have as many little ways as it would take to make up that ring. So, for a 4,005 node way, assuming a 1,000 node limit, you could have: * 10 1,000 node ways * 1 5 node way and: relation id=1 tag k=type v=multipolygon / member type=way id=1 role=outer / !-- 1-1000 -- member type=way id=2 role=outer / !-- 1001-2000 -- member type=way id=3 role=outer / !-- etc. -- member type=way id=4 role=outer / member type=way id=5 role=outer / /relation However, it is not clear that that is what Frederik meant in: http://lists.openstreetmap.org/pipermail/talk/2009-February/034091.html He suggested that the ways should be split up into smaller 'ways of managable size', but from what I've seen, these 'ways of managble size' are often closed polygons on their own: http://openstreetmap.org/browse/way/24417625/ Doing the former is easy. Doing the latter is hard, because figuring out how far you can go before 'drawing a line' to close the polygon is something I can't understand how to do. Imagine a 'C' shaped lake: --- | | | | | | | | |-- Creating closed chunks of that polygon, keeping the edges mostly as they are in the original, is not something I can imagine a way to do programatically. (I think that tesslating it into a bunch of triangles would be possible, but then you're really creating something that doesn't look at all like the output polygon.) Maybe Frederik was saying that the former is okay. My curiousity in that case is just if renderers -- especially Mapnik -- will actually support these things. (I can't imagine it working for osmarender, but that is less concenring to me.) If they won't, then adding the data like this may not be a good idea, simply because people will start doing wacky things to get data to show up in the map, messing up data... Is my concern clear? If it's the former, it's pretty easy to add to polyshp2osm, but the latter is hard... CCing talk@, since I assume frederik isn't on this list, and he can probably quickly tell me that I'm wrong in thinkign he might mean the latter. :) Regards, -- Christopher Schmidt MetaCarta ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] [Talk-us] NHD Dataset
Hi, Christopher Schmidt wrote: So, to be clear, what this looks like to me is that for any polygon, you can take the 'one long way' that would previously have outlined it, and instead of having that 'one long way', you have as many little ways as it would take to make up that ring. So, for a 4,005 node way, assuming a 1,000 node limit, you could have: * 10 1,000 node ways * 1 5 node way That's the idea. However, it is not clear that that is what Frederik meant in: http://lists.openstreetmap.org/pipermail/talk/2009-February/034091.html He suggested that the ways should be split up into smaller 'ways of managable size', but from what I've seen, these 'ways of managble size' are often closed polygons on their own: They are today, for practical reasons, but this is really not encouraged as it may lead to ugly border lines in the middle of areas. Maybe Frederik was saying that the former is okay. My curiousity in that case is just if renderers -- especially Mapnik -- will actually support these things. (I can't imagine it working for osmarender, but that is less concenring to me.) The JOSM build-in renderer already supports them, and there is a patch for Osmarender that does. And with so many bright minds at work on Mapnik it can only be a question of time until Mapnik supports that kind of relation as well. (The fact that, for stability, you should not rely on correct ordering of the relation's members even though 0.6 supports ordering makes things a *little* more difficult to process, but requiring correct ordering of editors and mappers would probably introduce too many errors.) There really is not much other choice, as areas grow larger and the old idea of simply drawing touching polygons relies on a rendering style without a casing around the polygon. Bye Frederik -- Frederik Ramm ## eMail frede...@remote.org ## N49°00'09 E008°23'33 ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] [Talk-us] NHD Dataset
Maybe Frederik was saying that the former is okay. My curiousity in that case is just if renderers -- especially Mapnik -- will actually support these things. (I can't imagine it working for osmarender, but that is less concenring to me.) The JOSM build-in renderer already supports them, and there is a patch for Osmarender that does. And with so many bright minds at work on Mapnik it can only be a question of time until Mapnik supports that kind of relation as well. (The fact that, for stability, you should not rely on correct ordering of the relation's members even though 0.6 supports ordering makes things a *little* more difficult to process, but requiring correct ordering of editors and mappers would probably introduce too many errors.) Mapnik already support this,see: http://openstreetmap.org/browse/relation/24849/ But production osmarender not yet: http://openstreetmap.org/?lat=49.6758lon=15.9996zoom=12layers=0B00FTF What's the problem with osmarender patch? Tomas Tichy ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
