Re: [Tagging] Landuse border alignment
Liz napsal(a): On Sat, 15 May 2010, Petr Morávek [Xificurk] wrote: and the last, most puzzling is landuse=basin An area of water that drains into a river wow, there are some pretty huge ones of those like the Amazon basin the Lake Eyre basin the Mississipi basin the fill_in_any_large_river basin so that would colour in most of the map really quickly if that was rendered That's where I'm confused, because if I understand correctly in hydrology it's an area from which the rain water drains into a river or lake, in that case what is this doing in landuse? This should be imho marked with boundary tag, furthermore mapnik renders this as a water (blue areas). What the heck is this tag for? Do we need it? And the rest of water tags is also in conflict with common sense, which tells me that the natural=water should be for lakes and non man-made ponds, the landuse=reservoir for all of the man-made bodies of water. But the wiki page [1] says something different. [1] http://wiki.openstreetmap.org/wiki/Tag:natural%3Dwater Regards, Petr Morávek signature.asc Description: OpenPGP digital signature ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
Personally I'm starting to use multipolygons more and more - define a boundary once and reuse is as many times as needed by the landuses either side. Steve - Original Message - From: Pieren To: Tag discussion, strategy and related tools Subject: Re: [Tagging] Landuse border alignment Date: Mon, 17 May 2010 14:51:15 +0200 On Mon, May 17, 2010 at 2:00 PM, Jonas Minnberg sas...@gmail.com wrote: I'm kind of considering if this is right or not - if a road is the divider between two landuses, is it still best to unglue it from the landuse(s) and move it into one or the other? It's best to unglue but it's also not wrong to glue the landuse. Some will say it's inaccurate, but hey, drawing a road with a polyline is also inaccurate. In some cases, ungluing can be worst : imagine two parallel streets and one pedestrian square in between. If you unglue the square, you need polylines to represent the roads connection (for e.g. pedestrian routing). These lines are inacurate because they can be drawn at some intervals only where physically the connection is everywhere along the square. If you glue the pedestrian square, your problem is easily solved and closer to the reality. Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging -- ___ Surf the Web in a faster, safer and easier way: Download Opera 9 at http://www.opera.com ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
On Mon, May 17, 2010 at 2:51 PM, Pieren pier...@gmail.com wrote: On Mon, May 17, 2010 at 2:00 PM, Jonas Minnberg sas...@gmail.com wrote: I'm kind of considering if this is right or not - if a road is the divider between two landuses, is it still best to unglue it from the landuse(s) and move it into one or the other? It's best to unglue but it's also not wrong to glue the landuse. Some will say it's inaccurate, but hey, drawing a road with a polyline is also inaccurate. In some cases, ungluing can be worst : imagine two parallel streets and one pedestrian square in between. If you unglue the square, you need polylines to represent the roads connection (for e.g. pedestrian routing). These lines are inacurate because they can be drawn at some intervals only where physically the connection is everywhere along the square. If you glue the pedestrian square, your problem is easily solved and closer to the reality. But then we are not talking about landuse, we are actually talking about a way, albeit a very wide one - and ways should be connected to each other. (And now we are back to the topic if ways should be areas... but thats another discussion :). ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
2010/5/16 Zeke Farwell ezeki...@gmail.com: On Sun, May 16, 2010 at 10:29 AM, M∡rtin Koppenhoefer dieterdre...@gmail.com wrote: IMHO yes, as natural is mainly about landcover (what you physically encounter on the spot) while landuse is about usage. If you want do some extremely detailed mapping you might make a lot of different non-overlapping polygons that represent what's on the ground exactly. However, I don't think that is really necessary or even correct. If there is a large residential area with some chunks of woods inside it should those chunks of woods not be considered residential land? I'm not sure whether to consider the wood residential land, after all that depends on the concrete situation, but I think that this is exactly what I wrote about: you could simply tag in a first approximasation the whole area as landuse=residential and at the same time draw the wood-polygon as landcover=wood (or natural=wood, or whatever). cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
2010/5/17 Pieren pier...@gmail.com: On Mon, May 17, 2010 at 2:00 PM, Jonas Minnberg sas...@gmail.com wrote: I'm kind of considering if this is right or not - if a road is the divider between two landuses, is it still best to unglue it from the landuse(s) and move it into one or the other? It's best to unglue but it's also not wrong to glue the landuse. Some will say it's inaccurate, but hey, drawing a road with a polyline is also inaccurate. can't follow you here: if some errors are inherent (missing curve-functions) we should put some other additional errors because it doesn't matter any more? In some cases, ungluing can be worst : imagine two parallel streets and one pedestrian square in between. If you unglue the square, you need polylines to represent the roads connection (for e.g. pedestrian routing). pedestrian squares are an exception (they are routable polygons). These lines are inacurate because they can be drawn at some intervals only where physically the connection is everywhere along the square. use an area-relation to model this is you want. The only situation where landuse and streets might be sharing the same nodes is when the street is mapped as an area (not tagged as highway but probably additionally to the abstract centre-lines (highway) we are needing for routing). cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
So the common problem I have here in Stockholm is that most residential areas in the suburbs have been carved out of wood- and grass-areas so there is always a mish-mash between those three. Is the correct way to split up all those landuses in smaller parts so they never overlap? Also, is it OK that natural overlaps landuse? It kind of has to be, since it's used a lot to place brushes or tree-areas inside larger landuses. -- Sasq ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
On Sun, May 16, 2010 at 10:14 PM, Jonas Minnberg sas...@gmail.com wrote: Also, is it OK that natural overlaps landuse? It kind of has to be, since it's used a lot to place brushes or tree-areas inside larger landuses. Sure. If a forest crosses a fenceline, then it overlaps. I did something like that here: http://www.openstreetmap.org/?lat=-37.86627lon=145.19352zoom=17layers=B000FTF Not that it renders particularly nicely. Steve ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
Also, in areas with sufficient rainfall, a former field will revert to forest within 20 years or so, assuming the farmer didn't let all of the topsoil erode away. -- John F. Eldredge -- j...@jfeldredge.com Reserve your right to think, for even to think wrongly is better than not to think at all. -- Hypatia of Alexandria -Original Message- From: Cartinus carti...@xs4all.nl Date: Sun, 16 May 2010 18:21:53 To: tagging@openstreetmap.org Subject: Re: [Tagging] Landuse border alignment On Sunday 16 May 2010 18:11:47 Anthony wrote: On Sun, May 16, 2010 at 11:31 AM, Steve Bennett stevag...@gmail.com wrote: On Sun, May 16, 2010 at 10:14 PM, Jonas Minnberg sas...@gmail.com wrote: Also, is it OK that natural overlaps landuse? It kind of has to be, since it's used a lot to place brushes or tree-areas inside larger landuses. Sure. If a forest crosses a fenceline, then it overlaps. Why would there be a fence within an unmaintained woodland? Fences are commonly used to demarcate ownership. unmaintained unowned -- m.v.g., Cartinus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
2010/5/14 Jonas Minnberg sas...@gmail.com: What about bordering buildings - ie buldings sharing walls but having different addresses/uses ? Is it better to draw the as a single area or as separate but with shared nodes? IMHO the more you can separate them, the better. Usually I would expect (in a final stage) each building as a separate area/relation and even parts of the same building but with different heights separately (because this is useful when making 3D, i.e. assigning heights to buildings). cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
Jonas Minnberg wrote: When is it OK to remove an overlapping landuse ? In some places I found 3 overlapping landuses and it's not clear which one has priority... When you have visited the area and found out what the real landuse is? Cheers, Chris ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
* Jonas Minnberg sas...@gmail.com [2010-05-14 16:39 +0200]: What about bordering buildings - ie buldings sharing walls but having different addresses/uses ? Is it better to draw the as a single area or as separate but with shared nodes? I feel that separate ways that share nodes along the joint wall makes the most sense from an accuracy standpoint. It allows you to tag the appropriate areas with the building's address and type, which can be useful, since the renderers can color different building types differently. I osciallate on how much I do this, though. For dense commercial/retail areas, I might make distinct ways for the largest buildings (a supermarket in a strip mall, for instance) and just a few other ways that encompass all the smaller buildings; for example: http://osm.org/go/ZcIoRxTbc- . For residential areas, I often don't even bother with the buildings; because they're so small, they take a lot of time to make. There are examples in the residential areas just east of the shopping center I linked above. -- ...computer contrarian of the first order... / http://aperiodic.net/phil/ PGP: 026A27F2 print: D200 5BDB FC4B B24A 9248 9F7A 4322 2D22 026A 27F2 --- -- The router thinks it's a printer. -- BOFH excuse #118 --- -- ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
Oh and I forgot: * landuse=grass overlapping landuse=wood, grass set as layer=-1 On Fri, May 14, 2010 at 9:26 PM, Jonas Minnberg sas...@gmail.com wrote: OK, some real world examples; * Two overlapping wood-areas, one named, the other not. * Grass inside grass landuse, rock inside grass landuse etc - is the rule that wholly interior (possibly sharing nodes with the exterior) areas are always rendered on top of its exterior area? ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
2010/5/14 Jonas Minnberg sas...@gmail.com: Oh and I forgot: * landuse=grass overlapping landuse=wood, grass set as layer=-1 is this inside a building or are there platforms or what is the purpose of this layer-tag? cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
On 15 May 2010 05:27, Jonas Minnberg sas...@gmail.com wrote: Oh and I forgot: * landuse=grass overlapping landuse=wood, grass set as layer=-1 Are you mixing up landuse and land cover by any chance? ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
2010/5/14 Jonas Minnberg sas...@gmail.com: OK, some real world examples; * Two overlapping wood-areas, one named, the other not. Generally it's a good idea to tidy up your area, given you know the area, so in this case: either you know the extent of the named area in real life, or you shouldn't touch it. * Grass inside grass landuse, rock inside grass landuse etc - is the rule that wholly interior (possibly sharing nodes with the exterior) areas are always rendered on top of its exterior area? no, there is no such rule and even if the rendering is correct, the mapping in the rock-grass case isn't: either there is grass or rocks, i.e. you should model a multipolygon-relation. Grass inside grass: are there any other tags? What is there (is the outer grass-polygon really completely grass?). Noone can give you hints just by reading tags and not seeing what is there or what is mapped exactly. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
2010/5/14 John Smith deltafoxtrot...@gmail.com: On 15 May 2010 05:27, Jonas Minnberg sas...@gmail.com wrote: Oh and I forgot: * landuse=grass overlapping landuse=wood, grass set as layer=-1 Are you mixing up landuse and land cover by any chance? you're insisting on this one? Yes, you are right: in traditional geoscience landuse is a precise term, it describes the usage of a given area in a generalized way. Unfortunately this is not true when it come to OSM: just open your eyes. Have you ever downloaded a piece of Berlin? You would be astonished ;-). Our landuse is often fragmented (IMHO not bad, because if there is different stuff, how else should you point that out? It is easier to summarize different landuses to one according to type and size than it is to divide 1 big generalized landuse automatically into all of it's subparts). How many landcover-tags are there in OSM? Is grass, garages or landfill a landuse? Another example: cut off (burned down) forest: this would probably still be called landuse=forest in an official map, but in OSM if there are no trees it will not be a forest. On the other hand: I would like to see this mess tidyed up. In this case I suggest to first change (extend) render rules and then encourage people to change tagging. This is all because of tagging for the renderers: because it is sad to tag correct and you don't see anything on the map ;-). I don't promote a cluttered or coloured map: I do promote rendering of lots of tags, but they don't have to get all different colours. Also few colours (i.e. many features/tags with the same colour) can be a way to do it. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Landuse border alignment
On Fri, May 14, 2010 at 9:50 PM, M∡rtin Koppenhoefer dieterdre...@gmail.com wrote: 2010/5/14 John Smith deltafoxtrot...@gmail.com: On 15 May 2010 05:27, Jonas Minnberg sas...@gmail.com wrote: Oh and I forgot: * landuse=grass overlapping landuse=wood, grass set as layer=-1 Are you mixing up landuse and land cover by any chance? you're insisting on this one? Yes, you are right: in traditional geoscience landuse is a precise term, it describes the usage of a given area in a generalized way. Eh, I am not insisting anything - that was an example of bad editing IMHO. There really should be tags for rendering-hints to mapnik - until mapnik handles everything. That way people could tag correctly and still get the appearance they wanted... Unfortunately this is not true when it come to OSM: just open your eyes. Have you ever downloaded a piece of Berlin? You would be astonished ;-). Our landuse is often fragmented (IMHO not bad, because if there is different stuff, how else should you point that out? It is easier to summarize different landuses to one according to type and size than it is to divide 1 big generalized landuse automatically into all of it's subparts). How many landcover-tags are there in OSM? Is grass, garages or landfill a landuse? Another example: cut off (burned down) forest: this would probably still be called landuse=forest in an official map, but in OSM if there are no trees it will not be a forest. On the other hand: I would like to see this mess tidyed up. In this case I suggest to first change (extend) render rules and then encourage people to change tagging. This is all because of tagging for the renderers: because it is sad to tag correct and you don't see anything on the map ;-). I don't promote a cluttered or coloured map: I do promote rendering of lots of tags, but they don't have to get all different colours. Also few colours (i.e. many features/tags with the same colour) can be a way to do it. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
