[OSM-newbies] Rendered two ways; why?

[Steve Dobson]

`	Hi Phil

Sorry for not replying sooner, work you know!

On 14/06/10 18:23, Phil! Gold wrote:
> * Steve Dobson<steve at dobbo.org>  [2010-06-14 06:31 +0100]:
>> I don't see why different tile servers are required.  One could have a
>> version of the tile for each symbol set.  That is a disk size issue to
>> me, not a multiple server issue, and disk space these days is cheap.
>
> The tiles take up a fair amount of space.  The main rendering server (as
> far as I can tell) is yevaud, which regularly runs at about 90% capacity
> (http://munin.openstreetmap.org/openstreetmap/yevaud.openstreetmap-df.html)
> of its tiles partition, which is 600GB total if I understand
> http://wiki.openstreetmap.org/wiki/Servers/yevaud correctly.

Well then disk wise it looks doable.  A little reconfiguration of yevaud 
would be needed but not impossible.  These days terabyte stores on 
servers is not unusual or that expensive.

>> I haven't looked at either Mapnik or Osmarendar but I can't believe that
>> it would be that difficult to modify they tile rendering code to go
>> though a look-up table.  It is, after all, a very common computer technique.
>
> I've loked at Mapnik, and I can believe it would be difficult.  Mapnik
> (essentially) takes a PostGIS database and a rendering config file and
> spits out PNGs with the rendered map.  To do as you want would require one
> of two things: either multiple config files with different icons for each
> region and everything else duplicated, or rendering a base PNG and
> multiple overlay PNGs for each icon set (each layer would have its own
> config file, but at least rules wouldn't be duplicated among them).  The
> former would require a lot more work to maintain the rules, so I doubt
> anyone would want to do it, while the latter would at least complicate the
> rendering process a lot.  I suspect this is an area where if you want to
> work out a process, you can try to convince people to start using your new
> process, but I doubt anyone is going to want to do just at your request.

To be honest I am not looking at running my own tile server.  Or of 
modifying the current software.  I just chipped in with my own thoughts 
when someone was pointing out that the current symbology could be 
interpreted different ways, which has to be true for any website that is 
aiming to be useful the world over.

Steve