On 19 April 2011 15:20, Andy Allan <[email protected]> wrote: > On Tue, Apr 19, 2011 at 3:05 PM, Matt Williams <[email protected]> wrote: > > On 19 April 2011 15:50, Andy Allan <[email protected]> wrote: > >> I'm assuming his map layers view has some logic that layers tags only > >> apply to ways that cross but I don't believe that to be true. > > > > Actually, that's exactly how I understood the layer tag to be used. It > > is simply there to disambiguate cases where there would otherwise be > > "z-fighting". > > But my point is that ways don't need to actually cross, they can just > be pretty close together (e.g. parallel), for the layer tags to be > useful and required. >
That is not what the wiki says (and said before my edits). Before my edits it said: "The layer Key can be used to mark if a way/node/area is above or under another one. "This tag should only be used for height differences that are real, like bridges over a street or tunnels under another object "When tagging things, try to avoid the layer tag most of the time. Especially do not use it in these circumstances: * Do not tag areas like landuse, natural etc. with a layer * Do not tag waterways like rivers, streams etc. with a layer just because you have a bridge running above them and do not want the bridge to be layer=1 "Remember: The layer tag has no meaning for absolute heights. The bridge within a perfectly flat street should be layer=1 even if the stream is as far below it as the Grand Canyon. The track on top of Mount Everest would be layer=0 even though it is 8848 meters above sealevel. In other words, the ground level, as would be shown on a topographic map, is always layer=0. "if two roads intersect in mid-air, they must both have the same layer to display properly. This means that it may be necessary to break one of them at a nearby point. http://wiki.openstreetmap.org/w/index.php?title=Key:layer&oldid=590097 In general I have be interpreting those rules across the area I mentioned. Regards, Peter > Cheers, > Andy > > _______________________________________________ > Talk-GB mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/talk-gb >
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