[Tilecache] Question about tilecache_seed.py with center locations

[Christopher Schmidt]

On Tue, Oct 14, 2008 at 01:12:11PM -0700, Andrew Wooster wrote:
> Hi all,
> 
> I'm attempting to use tilecache_seed.py to seed the cache using the center
> point/radius mode, and am having some difficulty.
> 
> My configuration looks like:
> [osm]
> type=Mapnik
> mapfile=/Users/andrew/Projects/OSM/mapnik_osm/osm.xml
> spherical_mercator=true
> tms_type=google
> metaTile=true
> metaSize=3,3
> 
> And I'm trying to use tilecache_seed like so:
> $ python tilecache_seed.py osm
> 25.791111,55.942778,0.08

Work in meters. You'll need to convert your lonlat and your radius:

2871053.343113143,7547032.796361966,3500

Would achieve about the same thing, I think.

> 
> Sadly, it appears that the cache is not being seeded properly with this
> method. As near as I can tell, at each zoom level it attempts to seed (5 -
> 16), it's picking the maximum tile position for both x and y at zoom z-1.

Actually, it's picking the tile just above and to the right of center at
each zoom level (the number ends up being the same as the previous zoom
level's size). This is because as far as TC is concerned you asked for a
1 meter wide box 50 meters from 0,0 :)

Regards,
-- 
Christopher Schmidt
MetaCarta