[Tilecache] A tilecache tutorial

[Adrian Zhao]

Brad:

I would assume that you need to translate the VE tile schema to WMS tile
request in order to use TileCache.

You can use GetCapabilities to request cached tile information before
you issue the GetMap call. 

Adrian

-----Original Message-----
From: tilecache-bounces at openlayers.org
[mailto:tilecache-bounces at openlayers.org] On Behalf Of Chris Holmes
Sent: Tuesday, February 27, 2007 5:41 PM
To: brad at cubewerx.com.au
Cc: tilecache at openlayers.org
Subject: Re: [Tilecache] A tilecache tutorial

Well, the hope (of at least some of us) is to get the pseudo-specs 
standardized, hopefully through an OGC process.  The WMS Tiling Client 
recommendation's main design goal was to be backwards compatible with 
existing WMS implementations, which it is.  As for OpenLayers being the 
only client, you've got to start somewhere.  I know uDig has 
experimented with it a bit.  And actually I believe CadCorp's client 
works against it as well.  Oh, and Worldkit, I should add that.  But 
with any standard it takes a good bit of time before there are lots of 
implementations.

If you're in a Google Maps or VE environment and you already had a WMS 
interface on top of them you'd just have to make sure it's requesting 
tiles according to the recommendation.  TileCache is strict in that it 
doesn't return any WMS data that doesn't follow the recommendations. 
Other servers may be more permissive.  But to take advantage of the 
static cache, yes you are going to have to write some additional code, 
since WMS doesn't constrain things enough for caching.  The hope in 
making the tiling client recommendation is that when clients start to 
want tiles from servers that they all ask for them in the same way.  And

then with caching we'll get enough performance out of WMS to actually be

feasible in terms of user experience on top of Google Maps or VE even if

people don't have huge servers.  Open Standards are basically for naught

if they can't hold a candle to the performance of other solutions.

The Tile Map Service is another pseudo-spec that TileCache implements, 
and if the experiment works and there is a diversity of servers and 
clients perhaps that will get pushed through OGC as well.

Chris

bradleyspencer wrote:
> Guys,
> 
> I understand the reason for static layers to be cached (interactive
> performance) but I was wondering when I read the wiki that currently
only OL
> can access TileCache? If I was working in a GoogleMaps environment or
VE
> environment and wanted to get access to an external static layer that
had
> been TileCached would someone have to build an interface from these
> environments to do so? This appears to me to introduce an
interoperability
> issue especially when I trying to avoid that by working in a open
standards
> (OGC) environment. Or have I missed something?
> 
> Cheers,
> 
> Brad Spencer
> General Manager
> CubeWerx Australia Pty Ltd
> ABN: 37 115 163 285
> Mob: +61 (0)404 841 131
> Tel/Fax: +61 (0)2 9481 7024
> mailto:brad at cubewerx.com.au
> http://www.cubewerx.com.au
> 
> -----Original Message-----
> From: Christopher Schmidt [mailto:crschmidt at metacarta.com]
> Sent: Wednesday, 28 February 2007 3:48 AM
> To: Chris Holmes
> Cc: tilecache at openlayers.org
> Subject: Re: [Tilecache] A tilecache tutorial
> 
> On Tue, Feb 27, 2007 at 11:33:32AM -0500, Chris Holmes wrote:
>> Hey all,
>>
>> I just wrote up a little tutorial for GeoServer users on how to set
up
>> TileCache and some tips and tricks I've learned during our
experiences
>> with it.  I meant to get this up awhile ago, and a decent bit that I
>> talk about made it in to the documentation for 1.4, but there may be
>> some helpful hints on setting up OpenLayers to take better advantage
of
>> TileCache.
>>
>> The tutorial is at:
>> http://docs.codehaus.org/display/GEOSDOC/TileCache+Tutorial
>>
>> Feel free to copy any information here to other locations, and I'm
fine
>> with this information living elsewhere, perhaps a more neutral place,
>> but I'll probably keep at least a copy as part of the GeoServer docs
so
>> users who download the docs get the information about TileCache.  And
>> also don't hesitate to add more tips and tricks, it's a wiki - just
hit
>> 'page operations -> edit page' on the left.
> 
> Thanks Chris -- I saw this on the GeoServer blog already, and was just
> about to comment and say that it looked great.
> 
> Regards,
> --
> Christopher Schmidt
> MetaCarta
> _______________________________________________
> Tilecache mailing list
> Tilecache at openlayers.org
> http://openlayers.org/mailman/listinfo/tilecache
> 
> 
> !DSPAM:1003,45e4a1f933207785049143!
> 

-- 
Chris Holmes
The Open Planning Project
http://topp.openplans.org