[OSM-talk] Kosmos 2.2

[Igor Brejc]

Frederik Ramm wrote:
> Igor,
>
>> I just want to inform you that a new version of Kosmos is out. For 
>> those interested, please read my blog post 
>> (http://igorbrejc.net/openstreetmap/kosmos-22) for more information 
>> about what's new in this release.
>
> I'm not a Kosmos user myself but sometimes I get queries from people 
> who want to render their own maps and depending on what type of user 
> they are I tend to send them in the Kosmos direction. Recently there 
> was one guy who wanted to do a rendering of the whole of Germany, and 
> I wasn't sure whether Kosmos could do that or not. Can you tell us 
> something about the resource usage of Kosmos - if I feed it the whole 
> of Germany, will it work but be slow, or will it break because it 
> cannot load it all into memory?
>
> Bye
> Frederik
>
Well the problem is that Kosmos loads all of the OSM data in memory - so 
running it with Germany as a whole would not work (how large is Germany 
OSM file, anyway?) on a "normal" machine - especially since OSM coverage 
of Germany is pretty detailed.
It was primarily designed to render maps interactively - so I haven't 
done any work on supporting OSM data from a database, for example. And 
to speed up the rendering, the OSM objects are transformed into map 
rendering entities (polylines, polygons, icons, etc) only once and then 
this too is stored in memory.
The largest area I've seen being rendered was Switzerland 
(http://scr3.golem.de/?d=0801/Kosmos&a=57077&s=9) more than 6 months ago.
As a test, I've just opened Slovenia OSM file (which includes large 
chunks of neighboring countries - 89 MB OSM file, 500,000 nodes): Kosmos 
GUI is burning 160 MB of RAM and it's working quite fast on my E6400 
machine.

Maybe in the future I'll explore how to support larger areas without 
loosing the interactivity.

Igor

-- 
http://igorbrejc.net