On Oct 13, 2012, at 5:41 AM, Frederik Ramm wrote:
> Mike,
>
> On 13.10.2012 00:40, Michal Migurski wrote:
>> * Generalized and merged dual carriageways for mid-zoom labels,
>> * City label placements for low-to-mid zooms generated with simulated
>> annealing,
>> * Route shields based on route relations,
>> * Merged transit points.
>
> There's often a tradeoff between making a beautiful map and making a current
> map. I have a feeling that some of the things you mention might actually
> incur quite a lot of processing time.
That is definitely the tradeoff I have in mind, yes.
> On OSM we're used to have "current" maps. Our default mapnik map updates just
> minutes after you have made a change. The tile layer guidelines for our front
> page say "Services maintaining minutely updates preferred, but periods up to
> two weeks may be acceptable depending on the content of the map.";
> help.openstreetmap.org is full of "I've made a change why doesn't it show"
> questions.
>
> Most of the current techniques for doing stuff like generalization are based
> on a "give me the full planet file and I'll render it" approach and are
> unsuitable for incremental updates; i.e. you would have to have a fat machine
> that generalizes the planet once every night or something.
I was thinking once per week or so, but yeah: the generalized parts would have
to be done on an offline basis periodically. It would take longer for changes
to migrate to this layer. It fills a need for better-looking, easier to use
cartography that isn't just a simple rasterization of the vectors in the
database, digitized as they are at a particular scale. It also keeps the
present Mapnik layer available for mappers, with its up-to-date content derived
from a live change stream.
Up-to-the-week is still quite "current" for most people's needs, and distinct
from the up-to-the-minute needs of mappers.
-mike.
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michal migurski- m...@stamen.com
415.558.1610
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