[Tilecache] TMS question

[Guillaume Sueur]

Thanks for this enlightment Klokan. One main point which confused me is
the ability of a gdal2tiles mercator cache to be displayed in
GoogleEarth. But I guess the kml does all the job. 
For Tilecache superoverlays to be usable on a 900913 cache, would it be
enough to transform the coordinates generated in the kml overlay in
degrees ? 

Best regards. 

Guillaume

Le mardi 12 janvier 2010 à 17:33 +0100, Klokan Petr Přidal a écrit :
> Hi Guillaume,
> 
> You are comparing address of the tiles in Mercator (EPSG:900913) and
> in Geodetic (EPSG:4326) TMS profiles. I guess your maptiler tiles are
> in "mercator" profile. To set up TileCache for mercator read this post
> from Chris:
> http://crschmidt.net/blog/archives/311/using-tilecache-with-google-maps-and-virtual-earth/
> 
> Here are same examples (proving the url is the same for both MapTiler
> and TileCache):
> 
> TMS "geodetic" (EPSG:4326) profile - examples:
> 
> - http://labs.metacarta.com/wms-c/tilecache.py/1.0.0/basic/4/16/12.png
> from http://www.tilecache.org/ website.
> - http://staremapy.mzk.cz/naturalearth/4/16/12.png
> from http://staremapy.mzk.cz/naturalearth/openlayers.html
> 
> TMS "mercator" (EPSG:900913 or EPSG:3857) profile - examples:
> 
> - http://hypercube.telascience.org/tiles/1.0.0/google-tiles/8/40/167.png
> from http://crschmidt.net/mapping/google-tilecache.html
> - http://www.klokan.cz/projects/gdal2tiles/overlay/8/40/167.png
> from http://www.klokan.cz/projects/gdal2tiles/overlay/openlayers.html
> 
> This mashup shows different tile names for mercator tiles:
> http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection/
> TMS Mercator is the default output of gdal2tiles/maptiler.
> 
> Best regards,
> 
> Klokan Petr Pridal
> 
> >> You're comparing an EPSG:4326 to a EPSG:900913 map... and thinking they'll
> >> have the same tile IDs? Is that what you're asking?
> >
> > Did I ? My confusion must invade my postings too then !
> > Here's what I'm trying to do exactly :
> > I have a huge gdal2tiles cache (EPSG:4326) over France, and I retrieve
> > the tiles from it throught standard TMS requests.
> > I have a TileCache of a WMS layer in EPSG:4326 and I want to overlay it
> > to the previous.
> > I thought, kindly, that using the same TMS request (i mean z/x/y.png) on
> > TC would send me back the correct tile. But it doesn't. At all.
> > Here is my Tc layer's definition :
> > type=WMS
> > url=some_url
> > layers=my_layer
> > extension=png
> > srs=EPSG:4326
> > extent_type=loose
> >
> > I can't guess where the problems comes from...
> >
> > Thanks for your help
> >
> > Guillaume
> >
> >>
> >> -- Chris
> >>
> >> > Regards
> >> >
> >> > Guillaume
> >> >
> >> >
> >> > Le lundi 11 janvier 2010 à 13:33 -0500, Christopher Schmidt a écrit :
> >> > > On Mon, Jan 11, 2010 at 03:42:35PM +0100, Guillaume Sueur wrote:
> >> > > > Hi,
> >> > > >
> >> > > > I'm wondering about the TMS grid used in TC. The request I see here
> >> > > > (http://labs.metacarta.com/wms-c/tilecache.py/1.0.0/basic/5/32/23.png)
> >> > > > doesn't match with what I see there
> >> > > > http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection/
> >> > > > for that area (north-east spain).
> >> > > >
> >> > > > Actually, does TileCache follow a specific TMS grid ?
> >> > >
> >> > > Not sure why you'd expect TMS and Google to be the same; Google is indexed
> >> > > from the top left corner, TMS from the bottom left.
> >> > >
> >> > > Regards,
> >> >
> >> >
> >> > _______________________________________________
> >> > Tilecache mailing list
> >> > Tilecache at openlayers.org
> >> > http://openlayers.org/mailman/listinfo/tilecache
> >>
> >
> >
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