[mkgmap-dev] Style for pipeline routes

Thu Nov 8 05:45:01 GMT 2018

Hi Dave,

this route=pipeline (1) discussion made me think about the rules in the relations style file.
I started like this:
1) Use the overpass api to download all relations with route=pipeline into JOSM (there are no too many of them)
2) Check those way members that are not tagged man_made=pipeline

Result:
- Some mappers use ways tagged as highway to build the pipeline route.
- Some mappers use ways tagged as man_made=cutline + cutline=pipeline
- Some mappers add objects like substations to the route
- Some mappers add waterway=canals

The idea behind the first 2 is obvious:
The pipeline is below or next to these ways, so why should I draw a new way. They transferred rules for multipolygons here.
The idea reg. substations is probably that they strongly relate to the pipeline, similar to a bus stop which is part of route=bus relation.
I did not yet understand the canals, but I am pretty sure there is also a reason for this.

Now, what does that mean for the style rules?
If we simply apply tags to the ways we risk that those ways are handled by only one rule in the lines file, e.g. that for the highway.
With the canals it might be the other way : we risk to render the pipeline instead of the canal.

If you care about that you have to add more rules to the lines file to handle those unexpected combinations, esp. if you want to render the pipeline
and the highway with the correct names.

Gerd

(1) http://gis.19327.n8.nabble.com/How-to-tag-named-group-of-named-water-areas-tp5923692p5926360.html

________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Dave Swarthout <daveswarthout at gmail.com>
Gesendet: Donnerstag, 8. November 2018 06:14
An: Development list for mkgmap
Betreff: [mkgmap-dev] Style for pipeline routes

Gerd,

Thanks for the help on the pipeline rendering. Your rule had one error in it, the word "way" but mkgmap complained and provided the line number of the error so it was easy to fix. I checked to see if the sections of the TAP pipeline where I removed the tags were rendered properly, and they were, even the sections that are underground or overground show up fine. Of course, those ways already carry the location tag. My line styles have provisions for both.

type=route & route=pipeline
    {
        apply {
        set man_made=pipeline;
        }
    }

During the long conversation about tagging relation members that began by trying to come up with a method of tagging groups of lakes. Someone suggested creating a new relation type of "group" to handle such things. I didn't want to do that so stuck with using a multipolygon to group a set of lakes that have a single name. Then I encountered a situation that was ideal for an experiment, three rocks near Kodiak Island that have the name "Three Sisters Rocks". These are nodes, not ways, so the multipolygon approach really doesn't suit them well. I create a new relation, tagged it as type=group and added the nodes to it. Of course, the rocks do not render on the OSM slippy map but they did on mymkgmap file because I added the following rule to the relations style sheet:

type=group & name=*
{
     apply {
       set name='${name}';
}
}

--
Dave Swarthout
Homer, Alaska
Chiang Mai, Thailand
Travel Blog at http://dswarthout.blogspot.com