Re: [talk-au] navit and bays/coastline around Sydney
I think putting the coastline (natural=coastline) across the mouth of a river (or a bay) is fine. This is quite common. - Ben. On 27 April 2011 19:16, Andrew Harvey wrote: > > Yep, and I added the coastline=imaginary tag to indicate that the line > tagged as coastline which crosses the mouth of the river is not a real > coastline, rather it is there to help existing software that doesn't > like breaks in the coastline. > > ___ Talk-au mailing list Talk-au@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] navit and bays/coastline around Sydney
On Tue, Apr 26, 2011 at 10:40 PM, Franc Carter wrote: >Yep - I will look in to that but from looking in to the code it looks >hard(ish) as I don't see a generic approach for dealing with ways that >are concatenated to form closed way. Navit would then have problems rendering any multipolygon relations made up of multiple segments. Though not all the area bays are like this some are just regular closed ways at the moment. > Yes, there is an examples of this across Port Hacking with a coastline > tag runnnig across open water. Conceptually wrong I think, but needed > in practice fro rendering to have any chance. Yep, and I added the coastline=imaginary tag to indicate that the line tagged as coastline which crosses the mouth of the river is not a real coastline, rather it is there to help existing software that doesn't like breaks in the coastline. ___ Talk-au mailing list Talk-au@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] navit and bays/coastline around Sydney
[snip] > > I've been aiming to tag bays as areas rather than just a node in the > centre. As a consequence my initial thought was to tag the area as > natural=bay. Traditionally most renderers didn't render this as water. > the OSM Mapnik style now does, but many others still don't. The > problem was I couldn't tag as both natural=water to get the rendering > and natural=bay to indicate the type of feature. Yes agreed, tagging the bay area seems like the right sort of thing to do. I've had the problem with mulitvalued tags before - the ';' approach seems rather hacky to me so I can understand why went for bay. > > I've since realised that tagging as natural=water, water=bay could be > a solution to use, but as natural=bay already had widespread use with > nodes, I wanted to keep consistency. > > As Markus_g mentioned you could try to edit Navits stylesheets so it > renders natural=bay areas as water (some times as a multipolygon), > although... Yep - I will look in to that but from looking in to the code it looks hard(ish) as I don't see a generic approach for dealing with ways that are concatenated to form closed way. > > I'm not opposed to your suggestion of keeping a kind of coastline tag, > I'm just not sure the best way to implement it, please discuss it if > you like. > > * Perhaps the coastline tag should be reserved for the ocean facing > coast. If we want to tag anything say inside a bay or harbour maybe we > could use a shoreline tag. Yes, this where the definitions aren't entirely clear to me. At some points we can say it's clearly coastline, at some points it's clearly riverbank, but the transition is not so clear. I suspect that the ways that make up a bay should be tagged with something, they mark a transition between water and not-water and the bay is the area inside these. The relation does this nicely. > * A problem with tagging the area of a bay is that while the shoreline > is mostly well defined, the other edge is fuzzy. A possible solution > is to use a multi polygon relation to tag just the non-shoreline > segments of the bay outline as fuzzy=*. I suppose that using a > multipolygon relation you can keep jest the shoreline segments > together in another relation for say a larger harbour or river Yes, there is an examples of this across Port Hacking with a coastline tag runnnig across open water. Conceptually wrong I think, but needed in practice fro rendering to have any chance. Not that it helps, but it occurs to me that the rendering model may be inverted. If the default was everywhere is water and then we have closed areas of land then things may go smoother - but tool late now ;-) Because of the way coastline rendering works I can't see a way to make things render correctly without having at least one hack (i.e the fake coastline boundary). The least hacky approach that I can see if for the water/non-water transition to be tagged coastline or riverbank (and shoreline if we can define it sensibly). At the point of transition there will need to be some tagging-for-the-rendere, but that's unavoidable. cheers > -- Franc ___ Talk-au mailing list Talk-au@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] navit and bays/coastline around Sydney
On Tue, Apr 26, 2011 at 8:28 PM, Franc Carter wrote: > Hi, > > I remember there was a discussion a while ago tagging of bays - which > I didn;t pay much attention too ;-( > > They now seem to be in a relation for each Bay, which is nice for > defining the area of the bay. However there are no tags on the ways > themselves and as a result Navit does nto render them as water, which > makes the map on Navit significantly less easy to use. > > My thought would be to put the coastline tag back on the ways and keep > the relations - any thoughts or suggestions on how to recover Navit > goodness ? I've been aiming to tag bays as areas rather than just a node in the centre. As a consequence my initial thought was to tag the area as natural=bay. Traditionally most renderers didn't render this as water. the OSM Mapnik style now does, but many others still don't. The problem was I couldn't tag as both natural=water to get the rendering and natural=bay to indicate the type of feature. I've since realised that tagging as natural=water, water=bay could be a solution to use, but as natural=bay already had widespread use with nodes, I wanted to keep consistency. As Markus_g mentioned you could try to edit Navits stylesheets so it renders natural=bay areas as water (some times as a multipolygon), although... I'm not opposed to your suggestion of keeping a kind of coastline tag, I'm just not sure the best way to implement it, please discuss it if you like. * Perhaps the coastline tag should be reserved for the ocean facing coast. If we want to tag anything say inside a bay or harbour maybe we could use a shoreline tag. * A problem with tagging the area of a bay is that while the shoreline is mostly well defined, the other edge is fuzzy. A possible solution is to use a multi polygon relation to tag just the non-shoreline segments of the bay outline as fuzzy=*. I suppose that using a multipolygon relation you can keep jest the shoreline segments together in another relation for say a larger harbour or river ___ Talk-au mailing list Talk-au@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] navit and bays/coastline around Sydney
Hi Franc, I had a look and Navit doesn't have natural=bay as a supported tag even though it is a supported tag in OSM. It might be worth contacting the developers of Navit and ask them to include the tag natural=bay from a relation to render as water. Regards, Markus -Original Message- From: Franc Carter [mailto:franc.car...@gmail.com] Sent: Tuesday, 26 April 2011 7:59 PM To: OSM Australian Talk List Subject: [talk-au] navit and bays/coastline around Sydney Hi, I remember there was a discussion a while ago tagging of bays - which I didn;t pay much attention too ;-( They now seem to be in a relation for each Bay, which is nice for defining the area of the bay. However there are no tags on the ways themselves and as a result Navit does nto render them as water, which makes the map on Navit significantly less easy to use. My thought would be to put the coastline tag back on the ways and keep the relations - any thoughts or suggestions on how to recover Navit goodness ? cheers -- Franc ___ Talk-au mailing list Talk-au@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-au ___ Talk-au mailing list Talk-au@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-au
[talk-au] navit and bays/coastline around Sydney
Hi, I remember there was a discussion a while ago tagging of bays - which I didn;t pay much attention too ;-( They now seem to be in a relation for each Bay, which is nice for defining the area of the bay. However there are no tags on the ways themselves and as a result Navit does nto render them as water, which makes the map on Navit significantly less easy to use. My thought would be to put the coastline tag back on the ways and keep the relations - any thoughts or suggestions on how to recover Navit goodness ? cheers -- Franc ___ Talk-au mailing list Talk-au@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-au
