Re: [OSM-talk] Parking aisle as boundary of car park not showing
On Wed, Sep 24, 2008 at 6:34 PM, Frederik Ramm [EMAIL PROTECTED] wrote: Hi, Adam Schreiber wrote: Not if you consider that roads are to be marked down their center line and typically the parking area ends to the outside of the center line of the road demarking their boundary. An argument that I would accept if we'd be tagging roads as areas. But as long as we tag roads as idealized zero-width lines which any renderer will draw as it sees fit, it does not make a lot of sense to let the area end precisely at the roadside. It makes more sense - to me - to place nodes with their actual latitude and longitude, so if the edge of the carpark is right here where I'm standing then marking it in the database as being somewhere 5-10m over to my left seems wrong. Same with two buildings either side of a road, where the edges of both are 10 metres apart, not touching down its centerline. This is because I'm in the centerline camp - those of use who believe we're marking the middle of the road for expedience's sake see no problem with a park - for cars or otherwise - coming up short of the road. And it means that areas preserve their actual dimensions instead of growing outwards beyond their actual boundary - an increasingly proportionately large problem as we add ever smaller details to OSM. Cheers, Andy ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
Hi, On 25.09.2008, at 12:03, Andy Allan wrote: And it means that areas preserve their actual dimensions instead of growing outwards beyond their actual boundary - an increasingly proportionately large problem as we add ever smaller details to OSM. But is that not a problem for roads as well? What use is it to have the car park exactly where it is in reality when the *road* next to it will grow outwards beyond its actual boundary because people thought in unnecessary to actually map the extent of the road surface? Bye Frederik -- Frederik Ramm ## eMail [EMAIL PROTECTED] ## N49°00'09 E008°23'33 ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
Andy quoted Frederik: An argument that I would accept if we'd be tagging roads as areas. But as long as we tag roads as idealized zero-width lines which any renderer will draw as it sees fit, it does not make a lot of sense to let the area end precisely at the roadside. And added: It makes more sense - to me - to place nodes with their actual latitude and longitude, so if the edge of the carpark is right here where I'm standing then marking it in the database as being somewhere 5-10m over to my left seems wrong. Same with two buildings either side of a road, where the edges of both are 10 metres apart, not touching down its centerline. I would agree, and if Frederik does want to tag roads as areas he could use the width= and/or est_width= tags, although it is unlikely that the renderers use them, assuming that the widths they currently render are based on just the highway= value and doesn't take into account any width tags (though I may be wrong). Ed ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
Hi, On 25.09.2008, at 12:23, Ed Loach wrote: I would agree, and if Frederik does want to tag roads as areas he could use the width= and/or est_width= tags, although it is unlikely that the renderers use them, assuming that the widths they currently render are based on just the highway= value and doesn't take into account any width tags (though I may be wrong). Well I don't necessarily want to tag roads as areas, I just want to map the fact that something (e.g. a forest) extends exactly up to the road. If the road is 0 metres wide (or as wide as the renderer wants it to be), then the only way to map this is to re-use the road centreline as a forest border. If the road had a left and right shoulder line then I could use that to delineate the forest border. It all boils down to whether the forest border and the road are independent of each other or whether you simply wanted to express the forest stops at the road (which is often the case for landuse or administrative areas, less often for forests). Bye Frederik -- Frederik Ramm ## eMail [EMAIL PROTECTED] ## N49°00'09 E008°23'33 ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
This is an interesting topic which is well worth discussion, but to return to the original question for a moment. The issue is that mapnik is not capable of rendering a way that is both a path and an area. The example given was highway=service, amenity=parking. Regardless of whether people are centerlineists or not, there are always going to be mappers who will tag ways this way. We have a free form tagging scheme so we cannot prohibit such things. For example, a way tagged as highway=waterway, power=line (two linear tags) might be unusual (water and electricity generally don't mix ;) but we cannot disallow it. So, if a way is tagged as highway=service to describe a road, but also amenity=parking to indicate that the road *is part of the car park and defines its boundaries* then that's the way it is. Suggesting that the data be changed to accommodate the deficiency of a particular renderer is very much a case of mapping for the renderer. This is a principle that is important to uphold. Fix the renderer not the data. Back to the centerlineist discussion... 80n On Thu, Sep 25, 2008 at 11:30 AM, Frederik Ramm [EMAIL PROTECTED] wrote: Hi, On 25.09.2008, at 12:23, Ed Loach wrote: I would agree, and if Frederik does want to tag roads as areas he could use the width= and/or est_width= tags, although it is unlikely that the renderers use them, assuming that the widths they currently render are based on just the highway= value and doesn't take into account any width tags (though I may be wrong). Well I don't necessarily want to tag roads as areas, I just want to map the fact that something (e.g. a forest) extends exactly up to the road. If the road is 0 metres wide (or as wide as the renderer wants it to be), then the only way to map this is to re-use the road centreline as a forest border. If the road had a left and right shoulder line then I could use that to delineate the forest border. It all boils down to whether the forest border and the road are independent of each other or whether you simply wanted to express the forest stops at the road (which is often the case for landuse or administrative areas, less often for forests). Bye Frederik -- Frederik Ramm ## eMail [EMAIL PROTECTED] ## N49°00'09 E008°23'33 ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
Frederik Ramm escribió: Hi, On 25.09.2008, at 12:23, Ed Loach wrote: I would agree, and if Frederik does want to tag roads as areas he could use the width= and/or est_width= tags, although it is unlikely that the renderers use them, assuming that the widths they currently render are based on just the highway= value and doesn't take into account any width tags (though I may be wrong). Well I don't necessarily want to tag roads as areas, I just want to map the fact that something (e.g. a forest) extends exactly up to the road. If the road is 0 metres wide (or as wide as the renderer wants it to be), then the only way to map this is to re-use the road centreline as a forest border. If the road had a left and right shoulder line then I could use that to delineate the forest border. It all boils down to whether the forest border and the road are independent of each other or whether you simply wanted to express the forest stops at the road (which is often the case for landuse or administrative areas, less often for forests). Bye Frederik in my opinion a more practical aproach is better. i think they must be independent because is easier to edit and correct in the future. a road around a forest can share nodes or the way can be tagged with bouth things, but if i buy land close to the road and take out the trees to build a house its easyer to edit just the landuse. so i would not do any of the cases. with JOSM i can zoom and put very close independent paths not touching each other making them practicaly coincident. the only case ill bother about what distance to draw it is if the barrier=fence finally gets aproved because maybe the road wich renders over the landuse will hide the fence if its to close to it. but again is up to each render the width of the road and if it renders differet width upon the number of lanes, there is even less control. sergio ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
80n wrote: This is an interesting topic which is well worth discussion, but to return to the original question for a moment. The issue is that mapnik is not capable of rendering a way that is both a path and an area. The example given was highway=service, amenity=parking. [...] Suggesting that the data be changed to accommodate the deficiency of a particular renderer is very much a case of mapping for the renderer. This is a principle that is important to uphold. Fix the renderer not the data. Getting into specifics a bit (they both qualify as the renderer), this is perhaps more an osm2pgsql issue than a Mapnik issue. cheers Richard ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
On Thu, Sep 25, 2008 at 11:58 AM, Richard Fairhurst [EMAIL PROTECTED]wrote: 80n wrote: This is an interesting topic which is well worth discussion, but to return to the original question for a moment. The issue is that mapnik is not capable of rendering a way that is both a path and an area. The example given was highway=service, amenity=parking. [...] Suggesting that the data be changed to accommodate the deficiency of a particular renderer is very much a case of mapping for the renderer. This is a principle that is important to uphold. Fix the renderer not the data. Getting into specifics a bit (they both qualify as the renderer), this is perhaps more an osm2pgsql issue than a Mapnik issue. Agreed. And something that should be fixed, right? cheers Richard ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
On Thu, Sep 25, 2008 at 12:47 PM, 80n [EMAIL PROTECTED] wrote: Suggesting that the data be changed to accommodate the deficiency of a particular renderer is very much a case of mapping for the renderer. This is a principle that is important to uphold. Fix the renderer not the data. It's not tagging for the renderer, it's Occam's razor : OSM tagging is a computer language and accommodating all kinds of seldom used quirks is bad practice. It will make it very difficult for an outsider to write and debug new software Back to the centerlineist discussion... Mungewell mentioned that he wants routing programs to be able to route through parking areas. So it's a good idea that the service way and the parking area share all the nodes. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
80n [EMAIL PROTECTED] wrote: Regardless of whether people are centerlineists or not, there are always going to be mappers who will tag ways this way. We have a free form tagging scheme so we cannot prohibit such things. For example, a way tagged as highway=waterway, power=line (two linear tags) might be unusual (water and electricity generally don't mix ;) but we cannot disallow it. That is true, but the good practice page in the wiki says One feature, one osm-object. So, noone should be too suprised if a renderer is only rendering either the waterway or the powerline. IMHO renderers should encourage good practices by not being to lax in what they render. I am just thinking of the problems arising from web browsers trying to render everything that looks vaguely like html. Christoph (Xoff) ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
Hi, On 25.09.2008, at 12:53, sergio sevillano wrote: with JOSM i can zoom and put very close independent paths not touching each other making them practicaly coincident. Exactly... and then someone comes along and makes the road a bit more accurate, and you force him to do the job twice OR leave a no-man's- land gap between road and forest. Bye Frederik -- Frederik Ramm ## eMail [EMAIL PROTECTED] ## N49°00'09 E008°23'33 ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
On Thu, Sep 25, 2008 at 12:13 PM, Christoph Boehme [EMAIL PROTECTED]wrote: 80n [EMAIL PROTECTED] wrote: Regardless of whether people are centerlineists or not, there are always going to be mappers who will tag ways this way. We have a free form tagging scheme so we cannot prohibit such things. For example, a way tagged as highway=waterway, power=line (two linear tags) might be unusual (water and electricity generally don't mix ;) but we cannot disallow it. That is true, but the good practice page in the wiki says One feature, one osm-object. So, noone should be too suprised if a renderer is only rendering either the waterway or the powerline. This is a distinction that will be lost on most casual mappers. Its complicated enough for them already. You are arguing for a scheme where seemingly arbitrary combinations of tags can or cannot be combined on one osm-object. highway=road can be shared with abutters=residential but cannot be shared with historic=battle because its an area (I'm thinking of things like http://en.wikipedia.org/wiki/Image:Concord_Retreat.png and http://en.wikipedia.org/wiki/Highway_of_Death both of which are battles that took place along roads). Where are these combination rules defined? Certain tag combination may or may not make sense, but there's no semantics in place to prohibit them. While I agree that it is good practice not to overload an object, renderers need to be tolerant and able to deal with unexpected tag combinations. 80n IMHO renderers should encourage good practices by not being to lax in what they render. I am just thinking of the problems arising from web browsers trying to render everything that looks vaguely like html. Christoph (Xoff) ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
On Thu, Sep 25, 2008 at 11:47 AM, 80n [EMAIL PROTECTED] wrote: This is an interesting topic which is well worth discussion, but to return to the original question for a moment. The issue is that mapnik is not capable of rendering a way that is both a path and an area. The example given was highway=service, amenity=parking. Regardless of whether people are centerlineists or not, there are always going to be mappers who will tag ways this way. We have a free form tagging scheme so we cannot prohibit such things. For example, a way tagged as highway=waterway, power=line (two linear tags) might be unusual (water and electricity generally don't mix ;) but we cannot disallow it. Umm... I don't like that argument. Saying we have a free form tagging scheme, and saying all the renderers should just cope with absolutely anything someone happens to have done are two very different things. We may not be able to disallow something, but we can sure as hell disagree with it and refuse to support it in a particular tool. Just because everything is allowed does not mean there is no such thing as wrong either, it just means our mechanisms for coping with it are different. So, if a way is tagged as highway=service to describe a road, but also amenity=parking to indicate that the road *is part of the car park and defines its boundaries* then that's the way it is. Suggesting that the data be changed to accommodate the deficiency of a particular renderer is very much a case of mapping for the renderer. This is a principle that is important to uphold. Fix the renderer not the data. And this is the point -- it's not a deficiency... as far as I'm concerned the car park has been incorrectly modelled. There is no sense in tagging a feature as both a line and an area... that way madness lies. And tagging a way/area with more than one feature can be just confusing. One feature per object is an entirely sensible rule that people are of course free to ignore... just don't expect anything to ever work if people make a regular habit out of it. The problem is that all sense of predictability has just been thrown out... does this represent a road around a car park, a road in a car park, an area of service road you can park on, or a centre line of a service road you can park on? Dave ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
On Thu, Sep 25, 2008 at 12:47 PM, 80n [EMAIL PROTECTED] wrote: This is a distinction that will be lost on most casual mappers. Its complicated enough for them already. You are arguing for a scheme where seemingly arbitrary combinations of tags can or cannot be combined on one osm-object. No he's not. He's arguing that arbitrary combinations of *real-world* objects should be avoided. Given that roads and parks are actually separate things, I'm sure we can spare a way for each of them. Cheers, Andy ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
On Thu, Sep 25, 2008 at 12:42 PM, Frederik Ramm [EMAIL PROTECTED] wrote: Hi, On 25.09.2008, at 12:53, sergio sevillano wrote: with JOSM i can zoom and put very close independent paths not touching each other making them practicaly coincident. This technique implies an accuracy that is normally unwarranted. How can you distinguish between someone using this zoomed in technique to indicate that a feature abuts a road and, say, Andy Allen armed with some high-tech wizardry, who is mapping it to 2cm precision? 80n Exactly... and then someone comes along and makes the road a bit more accurate, and you force him to do the job twice OR leave a no-man's- land gap between road and forest. Bye Frederik -- Frederik Ramm ## eMail [EMAIL PROTECTED] ## N49°00'09 E008°23'33 ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
On Thu, Sep 25, 2008 at 12:53 PM, Dave Stubbs [EMAIL PROTECTED]wrote: On Thu, Sep 25, 2008 at 11:47 AM, 80n [EMAIL PROTECTED] wrote: This is an interesting topic which is well worth discussion, but to return to the original question for a moment. The issue is that mapnik is not capable of rendering a way that is both a path and an area. The example given was highway=service, amenity=parking. Regardless of whether people are centerlineists or not, there are always going to be mappers who will tag ways this way. We have a free form tagging scheme so we cannot prohibit such things. For example, a way tagged as highway=waterway, power=line (two linear tags) might be unusual (water and electricity generally don't mix ;) but we cannot disallow it. Umm... I don't like that argument. Saying we have a free form tagging scheme, and saying all the renderers should just cope with absolutely anything someone happens to have done are two very different things. We may not be able to disallow something, but we can sure as hell disagree with it and refuse to support it in a particular tool. Just because everything is allowed does not mean there is no such thing as wrong either, it just means our mechanisms for coping with it are different. So, if a way is tagged as highway=service to describe a road, but also amenity=parking to indicate that the road *is part of the car park and defines its boundaries* then that's the way it is. Suggesting that the data be changed to accommodate the deficiency of a particular renderer is very much a case of mapping for the renderer. This is a principle that is important to uphold. Fix the renderer not the data. And this is the point -- it's not a deficiency... as far as I'm concerned the car park has been incorrectly modelled. There is no sense in tagging a feature as both a line and an area... that way madness lies. You're proposing that a field with a hedge around it should be tagged as two separate ways that share the same set of nodes right? A single object tagged with landuse=field, border=hedge seems pretty reasonable and intuitive to me. Where's the madness in this? In this case a renderer might choose to render the field as an area or the border as a line or, indeed, both. Sometimes it can be the renderer that needs to decide whether something is rendered as an area or a line or even a point. A roundabout being a good example where at some low zoom level it could be an icon, at another it's a filled in blob (an area), and at a high zoom level its a road with a hole in the middle. 80n And tagging a way/area with more than one feature can be just confusing. One feature per object is an entirely sensible rule that people are of course free to ignore... just don't expect anything to ever work if people make a regular habit out of it. The problem is that all sense of predictability has just been thrown out... does this represent a road around a car park, a road in a car park, an area of service road you can park on, or a centre line of a service road you can park on? Dave ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 80n wrote: On Thu, Sep 25, 2008 at 12:42 PM, Frederik Ramm [EMAIL PROTECTED] wrote: Hi, On 25.09.2008, at 12:53, sergio sevillano wrote: with JOSM i can zoom and put very close independent paths not touching each other making them practicaly coincident. This technique implies an accuracy that is normally unwarranted. How can you distinguish between someone using this zoomed in technique to indicate that a feature abuts a road and, say, Andy Allen armed with some high-tech wizardry, who is mapping it to 2cm precision? 80n indeed, who wants to? My 2p - I would separate them, the unglue tool in JOSM is good for this, and have them as distinct entities. I do it my way - My car parks look OK to me on the map, I like the data as it is, and the only reason I have seen to date in this thread to do it differently is Frederik's point about later edits needing both items to be moved. Fair, but not the end of the world... One of my reasons is that if I were to come in change it from one model to another, there is potential for data loss in reducing the node count, whereas an increase in nodes does not lose any data, but (if done accurately) improves it. I tend to regard loss of data in OSM as a bad thing, unless the world has really changed. Mark -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFI24UYJfMmcSPNh94RAguZAJ0Y4wf/ibttTXLGzXZcAzLCUpgYCACbBeXY FPzcZxgEIQW/r87NjHYvU1w= =N1LO -END PGP SIGNATURE- ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
On Thu, Sep 25, 2008 at 11:16 AM, Frederik Ramm [EMAIL PROTECTED] wrote: Hi, On 25.09.2008, at 12:03, Andy Allan wrote: And it means that areas preserve their actual dimensions instead of growing outwards beyond their actual boundary - an increasingly proportionately large problem as we add ever smaller details to OSM. But is that not a problem for roads as well? What use is it to have the car park exactly where it is in reality when the *road* next to it will grow outwards beyond its actual boundary because people thought in unnecessary to actually map the extent of the road surface? It is a problem for roads, but that's just an argument for mapping road areas. My main problem with mapping areas to the centre line (I'm not really counting landuse here, its possibly an exception) is the farcical situations to which it leads. The buildings example is the best: it's not uncommon at all to have a road abutted on both sides by buildings. If we map them to the centreline then we possibly increase their size by 50%, and happily record that they share a wall. Obviously they don't, and if you somehow figure out there's also a road in there, you might be able to reconstruct the real situation given a road width (which very few people actually record). So we say not to do it for buildings, but only for parks and car parks (I've seen this advice given). So now we have these sticking out into the road compared to a building right next to them. And there's lots of roads with grass verges; how big do they get before the object doesn't abut the road, and where is this width accounted for? The situation is confused greatly as soon as you try to map the park's fence or wall (if it exists): where's the road, inside or outside? Or we have a post box on the side of the road on the pavement: these are almost universally mapped as nodes where they are, rather than as a way node -- if we mapped to the centre line these post boxes are now inside the park? Or if the park diverges from the road at some point, do we maintain the offset and get the angles right, break the angles, or introduce an arbitrary curve? I get that the roads are being mapped as abstractions, and I get that it makes a lot of sense to stay abstracted, but on the whole I'd say the number of questions raised by this approach makes it a lot easier in the long run to just give up. We already break the abstraction for so many features precisely because coming up with tagging schemes to cope is just too hard, and because users find it so much easier to just plonk something on a satellite photo. Dave ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
On Thu, Sep 25, 2008 at 1:22 PM, 80n [EMAIL PROTECTED] wrote: On Thu, Sep 25, 2008 at 12:53 PM, Dave Stubbs [EMAIL PROTECTED] wrote: On Thu, Sep 25, 2008 at 11:47 AM, 80n [EMAIL PROTECTED] wrote: This is an interesting topic which is well worth discussion, but to return to the original question for a moment. The issue is that mapnik is not capable of rendering a way that is both a path and an area. The example given was highway=service, amenity=parking. Regardless of whether people are centerlineists or not, there are always going to be mappers who will tag ways this way. We have a free form tagging scheme so we cannot prohibit such things. For example, a way tagged as highway=waterway, power=line (two linear tags) might be unusual (water and electricity generally don't mix ;) but we cannot disallow it. Umm... I don't like that argument. Saying we have a free form tagging scheme, and saying all the renderers should just cope with absolutely anything someone happens to have done are two very different things. We may not be able to disallow something, but we can sure as hell disagree with it and refuse to support it in a particular tool. Just because everything is allowed does not mean there is no such thing as wrong either, it just means our mechanisms for coping with it are different. So, if a way is tagged as highway=service to describe a road, but also amenity=parking to indicate that the road *is part of the car park and defines its boundaries* then that's the way it is. Suggesting that the data be changed to accommodate the deficiency of a particular renderer is very much a case of mapping for the renderer. This is a principle that is important to uphold. Fix the renderer not the data. And this is the point -- it's not a deficiency... as far as I'm concerned the car park has been incorrectly modelled. There is no sense in tagging a feature as both a line and an area... that way madness lies. You're proposing that a field with a hedge around it should be tagged as two separate ways that share the same set of nodes right? A single object tagged with landuse=field, border=hedge seems pretty reasonable and intuitive to me. Where's the madness in this? Sounds pretty sensible to me too. Border implies it's a property of the field, and you don't normally use hedges for anything else. If we get really super accurate you /might/ find someone mapping hedge areas, and wondering whether you mapped the centre line or not, but I doubt it. Here's another: military=airfield, border=fence, fence_height=3, fence_type=chain_link_with_razorwire, highway=unclassified. Where's the fence/road? In this case a renderer might choose to render the field as an area or the border as a line or, indeed, both. Sometimes it can be the renderer that needs to decide whether something is rendered as an area or a line or even a point. A roundabout being a good example where at some low zoom level it could be an icon, at another it's a filled in blob (an area), and at a high zoom level its a road with a hole in the middle. Absolutely true. Dave ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
Greetings, The argument that we map street center lines and add width= or est_width= tags to give them an area is persuasive. Probably because that's what I already believed. ;-) We can also estimate width by using the highway= or lanes= tags. Mapping a car park to its edge (sidewalk, curb and gutter, etc.) also gives us something with an area. I suppose ways could even be drawn to show the entries to the car park. So... applications that use the data (renderers, etc.) should be able to deal with the case where the street center line is close to, but not coincident with, the bounds of an area such as a car park. The applications should also deal with the case where (part of) the bounds of an area is also a highway or waterway. Consider the case where a political boundary is defined by the center of a river. A single zero-width way serves as both the river center line and the political boundary. We have a similar case where a highway is carefully designed to follow a political boundary. It looks like we're back to map what's on the ground and our data consumers will use or ignore it as appropriate. -- - Joseph Scanlan http://www.qsl.net/n7xsd +1-702-455-3679 http://n7xsd.dyndns.org [EMAIL PROTECTED] (work) (not work) [EMAIL PROTECTED] - So he went inside there to take on what he found. But he never escaped them, for who can escape what he desires? --Tony Banks of Genesis in The Lady Lies ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
My main problem with mapping areas to the centre line (I'm not really counting landuse here, its possibly an exception) is the farcical situations to which it leads. The buildings example is the best: it's not uncommon at all to have a road abutted on both sides by buildings. If we map them to the centreline then we possibly increase their size by 50%, and happily record that they share a wall. Obviously they don't, and if you somehow figure out there's also a road in there, you might be able to reconstruct the real situation given a road width (which very few people actually record). One option may be to differentiate between; - a road, represented by a line and - a corridor, represented by an area. The corridor would be that area of land over which the relevant road authority has responsibility and control. Ie the road authority is in charge of not only the bitumen, but also the grass verge, drains, signs, flower stalls, etc... The road would exist inside the corridor, in fact multiple roads can exist inside a single corridor (think of complex intersections). Or a corridor could have no roads at all (think of a road that is planned, but not yet constructed). The road line would still be used for routing, but the road corridor would be used to define that area which is exclusively road, and which neighbouring features butt up against. But now we are talking about a cadastre map, not a street map. nick *** WARNING: This e-mail (including any attachments) may contain legally privileged, confidential or private information and may be protected by copyright. You may only use it if you are the person(s) it was intended to be sent to and if you use it in an authorised way. No one is allowed to use, review, alter, transmit, disclose, distribute, print or copy this e-mail without appropriate authority. If this e-mail was not intended for you and was sent to you by mistake, please telephone or e-mail me immediately, destroy any hardcopies of this e-mail and delete it and any copies of it from your computer system. Any right which the sender may have under copyright law, and any legal privilege and confidentiality attached to this e-mail is not waived or destroyed by that mistake. It is your responsibility to ensure that this e-mail does not contain and is not affected by computer viruses, defects or interference by third parties or replication problems (including incompatibility with your computer system). Opinions contained in this e-mail do not necessarily reflect the opinions of the Queensland Department of Main Roads, Queensland Transport or Maritime Safety Queensland, or endorsed organisations utilising the same infrastructure. *** ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
Mapnik doesn't recognise dual tags. In this case the area tag takes precedence. Separate polygon is the way to get it to show. Cheers STEVE Steve Chilton, Learning Support Fellow Manager of e-Learning Academic Development Centre for Learning and Quality Enhancement Middlesex University phone/fax: 020 8411 5355 email: [EMAIL PROTECTED] http://www.mdx.ac.uk/schools/hssc/staff/profiles/technical/chiltons.asp Chair of the Society of Cartographers: http://www.soc.org.uk/ SoC conference 2008: http://www.abdn.ac.uk/cartographers08/ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ed Loach Sent: 24 September 2008 16:12 To: 'LeedsTracker'; talk@openstreetmap.org Subject: Re: [OSM-talk] Parking aisle as boundary of car park not showing The boundary road is marked highway=service service=parking_aisle amenity=parking abutters=retail Whenever I've mapped car parks I've kept the area defined as amenity=parking as a separate polygon from any highway=service that may run around the outside of it. Map Features suggests that amenity=parking is a tag for nodes and/or areas, and that highway=service is a tag for ways. That [EMAIL PROTECTED] seems to cope doesn't necessarily mean that Mapnik can handle the dual tags. Ed ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
Thanks folks, Fixed with separate surrounding area. regards, LT 2008/9/24 Steve Chilton [EMAIL PROTECTED]: Mapnik doesn't recognise dual tags. In this case the area tag takes precedence. Separate polygon is the way to get it to show. Cheers STEVE Steve Chilton, Learning Support Fellow Manager of e-Learning Academic Development Centre for Learning and Quality Enhancement Middlesex University phone/fax: 020 8411 5355 email: [EMAIL PROTECTED] http://www.mdx.ac.uk/schools/hssc/staff/profiles/technical/chiltons.asp Chair of the Society of Cartographers: http://www.soc.org.uk/ SoC conference 2008: http://www.abdn.ac.uk/cartographers08/ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ed Loach Sent: 24 September 2008 16:12 To: 'LeedsTracker'; talk@openstreetmap.org Subject: Re: [OSM-talk] Parking aisle as boundary of car park not showing The boundary road is marked highway=service service=parking_aisle amenity=parking abutters=retail Whenever I've mapped car parks I've kept the area defined as amenity=parking as a separate polygon from any highway=service that may run around the outside of it. Map Features suggests that amenity=parking is a tag for nodes and/or areas, and that highway=service is a tag for ways. That [EMAIL PROTECTED] seems to cope doesn't necessarily mean that Mapnik can handle the dual tags. Ed ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk -- www.pollinger.org.uk PGP key: 0x30788FEF ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
On Wed, Sep 24, 2008 at 4:28 PM, Steve Chilton [EMAIL PROTECTED]wrote: Mapnik doesn't recognise dual tags. In this case the area tag takes precedence. Separate polygon is the way to get it to show. Isn't that tagging for the renderer? Cheers STEVE Steve Chilton, Learning Support Fellow Manager of e-Learning Academic Development Centre for Learning and Quality Enhancement Middlesex University phone/fax: 020 8411 5355 email: [EMAIL PROTECTED] http://www.mdx.ac.uk/schools/hssc/staff/profiles/technical/chiltons.asp Chair of the Society of Cartographers: http://www.soc.org.uk/ SoC conference 2008: http://www.abdn.ac.uk/cartographers08/ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ed Loach Sent: 24 September 2008 16:12 To: 'LeedsTracker'; talk@openstreetmap.org Subject: Re: [OSM-talk] Parking aisle as boundary of car park not showing The boundary road is marked highway=service service=parking_aisle amenity=parking abutters=retail Whenever I've mapped car parks I've kept the area defined as amenity=parking as a separate polygon from any highway=service that may run around the outside of it. Map Features suggests that amenity=parking is a tag for nodes and/or areas, and that highway=service is a tag for ways. That [EMAIL PROTECTED] seems to cope doesn't necessarily mean that Mapnik can handle the dual tags. Ed ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Parking aisle as boundary of car park not showing
On Wed, Sep 24, 2008 at 1:07 PM, 80n [EMAIL PROTECTED] wrote: On Wed, Sep 24, 2008 at 4:28 PM, Steve Chilton [EMAIL PROTECTED] wrote: Mapnik doesn't recognise dual tags. In this case the area tag takes precedence. Separate polygon is the way to get it to show. Isn't that tagging for the renderer? Not if you consider that roads are to be marked down their center line and typically the parking area ends to the outside of the center line of the road demarking their boundary. I have recently corrected several areas I have traced in my area because I had drawn them with their boundary along the center line of the road they abut. While they do indeed go right up to the sidewalk/road bounding them, they don't extend to the centerline of the road. Cheers, Adam ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
