[mapserver-users] Mapserver tile generation - google maps

Tue Aug 24 09:59:32 EDT 2010

Hi Wim,

If your data is that dynamic then there is not much advantage in using tilecache. Perhaps there is not much advantage in making tiled requests either. Applications asking for 256x256 pixel sized tiles from on-demand bases are generating rather a lot of load for Mapserver. There is an advantage on the user side because tiles are cached on the client side and panning is fluent. However, the feeling is not necessarily bad even if the client is making single tile WMS requests. With OpenLayers single tile requests used together with "transition effect resize" is not bad at all. Perhaps Google maps and Bing have some similar modes. Rendering and labeling problems should go away by using single tiles.

-Jukka Rahkonen-

> -----Alkuperäinen viesti-----
> Lähettäjä: mapserver-users-bounces at lists.osgeo.org 
> [mailto:mapserver-users-bounces at lists.osgeo.org] Puolesta 
> Stephen Woodbridge
> Lähetetty: 24. elokuuta 2010 16:43
> Vastaanottaja: mapserver-users at lists.osgeo.org
> Aihe: Re: [mapserver-users] Mapserver tile generation - google maps
> 
> Tilecache probably is not what you want if you have very 
> dynamic tiles. 
> Or at least a tile cache that is persistent.
> 
> Your problem is with tile edge artifacts. It might be 
> possible to draw 
> on a slightly larger image than the tile, then cut the tile 
> out of it to 
> avoid some of those, but there are some tile artifacts that 
> you can not 
> get away from when you draw single tiles, like label positioning and 
> label thinning over multiple tiles.
> 
> For an alternative, you might look to mapscript where you could have 
> more programmatic control over the rendering and do things 
> like render a 
> larger image than needed and cut out the tile like I mentioned.
> 
> You might also write a bug against mode=tile and see what the 
> developer 
> response to that might be.
> 
> -Steve W
> 
> On 8/24/2010 8:04 AM, Wim Vanbelle wrote:
> > For reference sake:
> >
> > The issue is also present when using Bing maps as overlay.
> > I also recompiled mapserver against agg 2.5 and gd-2.0.36RC1, but no
> > change unfortunately.
> >
> > As stated in my previous mail, I may have to look for 
> alternatives as
> > the tilecache will probably not be an option for us.
> >
> > Would it be possible to circumvent this problem by using WMS?
> >
> >
> >
> >
> > On 24 August 2010 07:25, Wim Vanbelle <wimvanbelle at gmail.com
> > <mailto:wimvanbelle at gmail.com>> wrote:
> >
> >     Hi,
> >
> >     Thank you for your time both.
> >
> >     Wouldn't using tilecache imply that I can no longer use dynamic
> >     data? My tiles have to update every minute. Perhaps 
> this is possible
> >     with tilecache? Basically it's only the color value 
> that changes for
> >     each object.
> >
> >     An example request that is sent to mapserver:
> >
> >     
> http://...maps?map=/.../white.map&layers=%20&mode=tile&tilemod
e=gmap&tile=264+172+9
> >
> >     MapServer version 5.6.5 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG
> >     OUTPUT=WBMP OUTPUT=SWF OUTPUT=SVG SUPPORTS=PROJ SUPPORTS=AGG
> >     SUPPORTS=FREETYPE SUPPORTS=ICONV SUPPORTS=FRIBIDI
> >     SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER
> >     SUPPORTS=WFS_CLIENT SUPPORTS=WCS_SERVER SUPPORTS=SOS_SERVER
> >     SUPPORTS=FASTCGI SUPPORTS=THREADS SUPPORTS=GEOS 
> SUPPORTS=RGBA_PNG
> >     INPUT=EPPL7 INPUT=POSTGIS INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE
> >
> >     My mapfile is configured like this:
> >
> >              OUTPUTFORMAT
> >                      NAME "AGGPNG"
> >                      DRIVER "AGG/PNG"
> >                      EXTENSION "png"
> >                      MIMETYPE "image/png;mode=24bit;"
> >                      IMAGEMODE RGBA
> >                      FORMATOPTION "INTERLACE=false"
> >                      FORMATOPTION "QUANTIZE_NEW=ON"
> >                      FORMATOPTION "QUANTIZE_FORCE=ON"
> >                      FORMATOPTION "QUANTIZE_DITHER=ON"
> >                      FORMATOPTION "QUANTIZE_COLORS=256"
> >              END
> >
> >     Although I've used GD as well.  Not sure how I can 
> check the GD &
> >     AGG versions.
> >
> >     I was in the process of making a new build for 
> mapserver with the
> >     lastest versions of everything though. I'll let you know if that
> >     would somehow fix the problem.
> >
> >
> >
> >
> >
> >     On 24 August 2010 06:45, Stephen Woodbridge 
> <woodbri at swoodbridge.com
> >     <mailto:woodbri at swoodbridge.com>> wrote:
> >
> >         If you are using mode=tile, then this is a known 
> limitation on
> >         the mapserver side. There is a plan for 6.0 to add tilecache
> >         support to mapserver that would allow you to 
> generate meta tiles
> >         and chop the tiles into a tilecache which is the 
> way to resolve
> >         the artifacts you are seeing.
> >
> >         http://trac.osgeo.org/mapserver/ticket/3513
> >
> >         You can add yourself the CC on this bug if you want 
> to follow
> >         it. There is also an RFC for the mode=tile which I 
> don't have
> >         handy that should give you more information on the 
> limitations
> >         and feature of that.
> >
> >         Hope this helps,
> >           -Steve W
> >
> >
> >         On 8/24/2010 12:34 AM, Lime, Steve D (DNR) wrote:
> >
> >             What mapserver version, what graphics driver? 
> Is this using
> >             mode=tile?
> >
> >             Steve ________________________________________ From:
> >             mapserver-users-bounces at lists.osgeo.org
> >             <mailto:mapserver-users-bounces at lists.osgeo.org>
> >             [mapserver-users-bounces at lists.osgeo.org
> >             
> <mailto:mapserver-users-bounces at lists.osgeo.org>] On Behalf
> >             Of Wim Vanbelle
> >             [wimvanbelle at gmail.com 
> <mailto:wimvanbelle at gmail.com>] Sent:
> >             Friday, August 20, 2010 6:26 AM To:
> >             mapserver-users at lists.osgeo.org
> >             <mailto:mapserver-users at lists.osgeo.org> Subject:
> >             [mapserver-users] Mapserver
> >             tile generation - google maps
> >
> >             Hi all,
> >
> >             I noticed a similar post regarding symbol 
> issues, but there
> >             was no
> >             solution. My Google maps tiles are currently 
> clipped at the tile
> >             itself. This results in rather unwanted behaviour:
> >
> >             http://fileshare.myroute.be/exchange/Capture.PNG
> >
> >             I'm not 100% sure that this is mapservers' 'issue' , or
> >             google maps
> >             issue.
> >
> >             If anyone would have further tips to spice up 
> the graphics
> >             even more,
> >             I'd be more than glad to hear them :).
> >
> >             Thanks. Wim 
> _______________________________________________
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> mapserver-users at lists.osgeo.org
> >             <mailto:mapserver-users at lists.osgeo.org>
> >
> >             http://lists.osgeo.org/mailman/listinfo/mapserver-users
> >
> >
> >
> >
> >
> >
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