RE: [mapserver-users] Mapserver images doesn't fit well on a tiling scheme‏

[Nelson Correia]

 I'm not sure if I got it right... When I request a 3x3 meta tile grid, tilecache only caches the center image? What if I request the image on the right of it and again another image to the right? Tilecache will issue new and overlapped requests to Mapserver? Or for the second request it will reuse a tile from the previous 3x3 request?

 


Date: Tue, 3 Mar 2009 06:46:58 -0800
From: danlittle at yahoo.com
Subject: Re: [mapserver-users] Mapserver images doesn't fit well on a tiling scheme‏
To: nelsonwc7 at hotmail.com; mapserver-users at lists.osgeo.org





I think you're a bit wrong there.  If you build the Cache using tilecache, when you use the "metaTiles" it will take a larger sample than the image being generated, for example if you have a 3x3 meta tile grid, the "center" tile of the nine-tile grid will be used.  I had the exact same problem you are describing, but then setup the tilecache generator to use metatiles and things started to work beautifully -- including labels.





From: Nelson Correia <nelsonwc7 at hotmail.com>
To: mapserver-users at lists.osgeo.org
Sent: Tuesday, March 3, 2009 8:11:16 AM
Subject: RE: [mapserver-users] Mapserver images doesn't fit well on a tiling scheme‏




 
With metaTile I can issue a pre-defined number of tiles that fit well. But this is per-request (if I'm right). For instance, if I make two consecutive requests of 4 tiles each from consecutive map zones, I get two sets of tiles that does not fit with each other (the first 4 do not fit side by side with the second 4).
 
The problem with that approach is that tiles from the same request fit well, but in order to construct a map like VE or Google Maps I need that tiles from different requests to always fit well.
 
Please tell me If I am wrong.
 


Date: Tue, 3 Mar 2009 05:44:05 -0800
From: danlittle at yahoo.com
Subject: Re: [mapserver-users] (no subject)
To: nelsonwc7 at hotmail.com; mapserver-users at lists.osgeo.org





Check the documentation on the "metaTile" it requires having PIL installed but that is not really a big hassle.




From: Nelson Correia <nelsonwc7 at hotmail.com>
To: mapserver-users at lists.osgeo.org
Sent: Tuesday, March 3, 2009 6:17:10 AM
Subject: [mapserver-users] (no subject)

Hi,
 
We are using Mapserver to produce tiles for a web application, using Tilecache as the caching mechanism. 
 
When we were building the system, we figured out that tiles requested does not fit well side by side (the roads of one tile does not fit the prolongation of the same road in the next tile). To eliminate this issue, we had to issue an extra 10 pixels (around the whole tile) request to Mapserver and then cut them. 
 
Then another problem arose: we could not make this with the labels because they appeared cut in one tile and there was no prolongati on of it on the next tile. The solution was to divide it into different layers: one for the roads with the 10 pixels buffer and another for the labels without buffer. This has the impact of duplicating the total number of images.
 
Anyone known an alternate solution for this problem?
 
Isn't Mapserver capable of serving images that fit well side by side?
 
Thanks in advance!

_________________________________________________________________
Drag n’ drop—Get easy photo sharing with Windows Live™ Photos.

http://www.microsoft.com/windows/windowslive/products/photos.aspx
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/mapserver-users/attachments/20090303/638ef7b4/attachment.htm>