[OSM-dev] Migrating osm.org to vectors/Kartotherian

[Christoph Hormann]

On Friday 30 October 2015, Yuri Astrakhan wrote:
>
> Kartotherian <https://github.com/kartotherian/kartotherian>, the
> Mapnik+Mapbox-based vector service has been implemented and
> trial-launched <https://maps.wikimedia.org/> at Wikipedia. The
> service itself is fairly stable, but the styles can use some
> improvements - both the sql->vtile
> <https://github.com/kartotherian/osm-bright.tm2source> and
> vtile->image <https://github.com/kartotherian/osm-bright.tm2>.
> Hopefully this work can be used as the basis for the osm.org style.
> Once the vtiles are ready, we can easily move to client side WebGL
> rendering.

From my perspective this, i.e. imposing a certain technological 
framework on designers based on technological considerations, is the 
wrong approach.  I wrote about this on my blog recently from a slightly 
different angle[1].  For a high quality style, design development has 
to mandate the technological framework, not the other way round.

If you look at design problems recently discussed in the osm-carto style 
development[2] you will see most of them have nothing to do with vector 
tiles, they would not be made any easier to address with such an 
approach.  On the other hand there are a multitude of things the 
current style handles fairly gracefully, especially the problem of 
reducing geometric complexity, that would be much harder to deal with 
in a vector tiles system[3].

In general it seems to me vector tiles are today often carried as some 
kind of religious mantra promising to be the solution of all problems 
while in reality they certainly are not.  It is better to look for and 
identify actual design problems and see what technological means are 
available to solve them.  So far use of vector tiles seem to primarily 
have lead to the following effects:

- improved tile serving efficiency
- a larger bandwidth of style variations
- tighter contraints in basic styling decisions beyond what is already 
imposed by the OSM data model

In short: from a design perspective vector tiles so far brought more 
variety in map styles but they ultimately all look very similar beyond 
superficial aspects.  Nearly all of the more unusual maps that 
currently exist are not vector tile based.

[1] http://blog.imagico.de/map-design-economics/
[2] https://github.com/gravitystorm/openstreetmap-carto
[3] For another example of where wikimedia maps fails miserably here 
see:
https://maps.wikimedia.org/#18/47.99579/7.85194
http://www.openstreetmap.org/#map=18/47.99579/7.85194

-- 
Christoph Hormann
http://www.imagico.de/