Quantcast

Rendering national/regional walking trails

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
8 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Rendering national/regional walking trails

Elizabeth Oldham
I am trying to render the national and regional walking trails. These
are done as relations, with tags like network=rwn so easy to pick out.
When I render them I find there are alternative routes, as an example
the Coast to Coast Walk splits into 3 at one point. Looking at the
relation in josm I find they have a "role" of alternative, or main as
appropriate.

However, I don't seem to be able to get at the "role", and there is
nothing else which distinguishes main from alternative routes - so I can
render them differently.

Have I missed anything obvious?

Thanks
Beth

_______________________________________________
Talk-GB mailing list
[hidden email]
https://lists.openstreetmap.org/listinfo/talk-gb
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Rendering national/regional walking trails

Paul Berry
Hi Beth,

Roles apply to the members of relation (which are almost always ways), not the relation itself, if that helps.

In theory a route such as this should be mapped as a parent route_master relation with all variations of that route as child relations. In practice this is somewhat rare: https://wiki.openstreetmap.org/wiki/Relation:route_master

I assume you're looking at https://www.openstreetmap.org/relation/12145 ?

Regards,
Paul

On 21 April 2017 at 11:26, Elizabeth Oldham <[hidden email]> wrote:
I am trying to render the national and regional walking trails. These are done as relations, with tags like network=rwn so easy to pick out. When I render them I find there are alternative routes, as an example the Coast to Coast Walk splits into 3 at one point. Looking at the relation in josm I find they have a "role" of alternative, or main as appropriate.

However, I don't seem to be able to get at the "role", and there is nothing else which distinguishes main from alternative routes - so I can render them differently.

Have I missed anything obvious?

Thanks
Beth

_______________________________________________
Talk-GB mailing list
[hidden email]
https://lists.openstreetmap.org/listinfo/talk-gb


_______________________________________________
Talk-GB mailing list
[hidden email]
https://lists.openstreetmap.org/listinfo/talk-gb
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Rendering national/regional walking trails

Andy Townsend
In reply to this post by Elizabeth Oldham
On 21/04/2017 11:26, Elizabeth Oldham wrote:

> I am trying to render the national and regional walking trails. These
> are done as relations, with tags like network=rwn so easy to pick out.
> When I render them I find there are alternative routes, as an example
> the Coast to Coast Walk splits into 3 at one point. Looking at the
> relation in josm I find they have a "role" of alternative, or main as
> appropriate.
>
> However, I don't seem to be able to get at the "role", and there is
> nothing else which distinguishes main from alternative routes - so I
> can render them differently.

If you're using osm2pgsql to load a rendering database, then you could
probably use the lua tag transforms and do something with roles for
relations in there.  I've not done anything with relation roles myself,
but
https://github.com/SomeoneElseOSM/SomeoneElse-style/blob/master/style.lua 
is a lua tag transform I use and
https://github.com/SomeoneElseOSM/SomeoneElse-style/blob/master/style.lua#L2296 
is the "relations" part of that, with "roles" as an array argument
passed in.  You could use that to add a "pseudo-tag" like I do with
"network=lwn" to get that to appear as a "highway", then render that as
per e.g.:
https://map.atownsend.org.uk/maps/map/map.html#zoom=14&lat=54.38373&lon=-1.51698 
.

Best Regards,

Andy


_______________________________________________
Talk-GB mailing list
[hidden email]
https://lists.openstreetmap.org/listinfo/talk-gb
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Rendering national/regional walking trails

Elizabeth Oldham
On 21/04/17 11:47, Andy Townsend wrote:

> If you're using osm2pgsql to load a rendering database,

Yes, sorry, I should have said.

> probably use the lua tag transforms and do something with roles for
> relations in there.  I've not done anything with relation roles myself,
> but
> https://github.com/SomeoneElseOSM/SomeoneElse-style/blob/master/style.lua
> is a lua tag transform I use and
> https://github.com/SomeoneElseOSM/SomeoneElse-style/blob/master/style.lua#L2296
> is the "relations" part of that, with "roles" as an array argument
> passed in.  You could use that to add a "pseudo-tag" like I do with
> "network=lwn" to get that to appear as a "highway", then render that as
> per e.g.:
> https://map.atownsend.org.uk/maps/map/map.html#zoom=14&lat=54.38373&lon=-1.51698

That looks useful. Thanks. I'll see if I can figure out what its doing.
Good map, BTW.

Beth

_______________________________________________
Talk-GB mailing list
[hidden email]
https://lists.openstreetmap.org/listinfo/talk-gb
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Rendering national/regional walking trails

Elizabeth Oldham
In reply to this post by Andy Townsend
On 21/04/17 11:47, Andy Townsend wrote:

> If you're using osm2pgsql to load a rendering database, then you could
> probably use the lua tag transforms and do something with roles for
> relations in there.  I've not done anything with relation roles myself,

It was an interesting exercise to play with it yesterday, but I
concluded it's only useful if you want to play with the tags applied to
the whole relation. Not just parts of the relation. So I could look at
the role, and the tags associated with the members, but not actually
change what is put into the database for only some of the route/relation.

Anyway. I noticed on your maps you have multiple ldpnwn labels along the
routes, like the Cumbria Way, and Coast to Coast. I've been unable to
get more than one or two labels. I've been searching but it's usually
the other way around - you have too many labels and need to space them
out. Is there a trick I'm missing?

Thanks
Beth


_______________________________________________
Talk-GB mailing list
[hidden email]
https://lists.openstreetmap.org/listinfo/talk-gb
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Rendering national/regional walking trails

Andy Townsend
On 22/04/2017 20:43, Elizabeth Oldham wrote:

Anyway. I noticed on your maps you have multiple ldpnwn labels along the routes, like the Cumbria Way, and Coast to Coast. I've been unable to get more than one or two labels. I've been searching but it's usually the other way around - you have too many labels and need to space them out. Is there a trick I'm missing?

I may have got hold of completely the wrong end of the stick here, but assuming I understand the question properly, I think you're asking how two names appear for trails at e.g. https://map.atownsend.org.uk/maps/map/map.html#zoom=14&lat=53.14563&lon=-1.75507 ?

What's happening is that at https://github.com/SomeoneElseOSM/SomeoneElse-style/blob/master/style.lua#L2320 a "highway=ldpnwn" tag is being added for each relation, and then at https://github.com/SomeoneElseOSM/openstreetmap-carto-AJT/blob/master/roads.mss#L1705 the purple dots are added, and at https://github.com/SomeoneElseOSM/openstreetmap-carto-AJT/blob/master/roads.mss#L3088 the text-spacing defines how far apart the labels go.

Because they are "just highways that happen to overlap each other" as far as Mapnik is concerned, it makes sure that the names don't overlap on the map.   I wrote a diary entry at http://www.openstreetmap.org/user/SomeoneElse/diary/38988 about it.

Best Regards,

Andy



_______________________________________________
Talk-GB mailing list
[hidden email]
https://lists.openstreetmap.org/listinfo/talk-gb
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Rendering national/regional walking trails

Elizabeth Oldham
On 23/04/17 09:55, Andy Townsend wrote:

> I may have got hold of completely the wrong end of the stick here, but
> assuming I understand the question properly, I think you're asking how
> two names appear for trails at e.g.
> https://map.atownsend.org.uk/maps/map/map.html#zoom=14&lat=53.14563&lon=-1.75507

It's not so much that two different names appear, and not overwrite one
another. But for each relation you get multiple labels along the route.
I'm getting very few labels on a particular route.

You can see my example here, where I've got the Cumbria Way.

http://openmaps.the-hug.net/?&m=330478.34705711|530841.03293706|7

I get 3 labels over the whole length. One near Carlisle, one between
Skiddaw House and Mosedale, and another the other side of Coniston. Now
this as it happens is using my own table imported from a shapefile.

However, the effect is the same when I do use the osm tables (I haven't
made it live yet). I tried pulling out snippets of your ldpnwn specif
code putting them into mine. But I still get only a few labels rendered.
My stylesheet for rendering ldpnwn is similar to yours. So I'm kind of
confused as to where the magic is that places multiple labels instead of
just a few?

Thanks,
Beth

_______________________________________________
Talk-GB mailing list
[hidden email]
https://lists.openstreetmap.org/listinfo/talk-gb
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Rendering national/regional walking trails

Andy Townsend


On 23/04/17 11:43, Elizabeth Oldham wrote:
> ... But I still get only a few labels rendered. My stylesheet for
> rendering ldpnwn is similar to yours. So I'm kind of confused as to
> where the magic is that places multiple labels instead of just a few?

The "text-spacing" settings below
https://github.com/SomeoneElseOSM/openstreetmap-carto-AJT/blob/master/roads.mss#L3088 
should control that.  When I was testing it I adjusted it up and down
until the spacing was about right.  I was using TileMill at that point
to test changes so it worked with Mapnik v2 and am now using it with
Mapnik v3, so it shouldn't be a Mapnik version problem.  With TileMill
(or Kosmtik) style changes should apply and be displayed immediately.

Other possibilities would be some sort of tile caching issue, but you've
no doubt already looked into that?  Maybe just change the name to
"something else" to make absolutely sure that a new name is rendered,
but still too infrequently.

Best Regards,

Andy


_______________________________________________
Talk-GB mailing list
[hidden email]
https://lists.openstreetmap.org/listinfo/talk-gb
Loading...