[Tilecache] Huge dateline gap

[Roger André]

Christopher,

That seems to have fully cured the edge problems - both at the dateline, as
well as at the South extent. Thanks again for your help.

 I have a suggestion.  Would it be possible to take the information in the
current http://tilecache.org/readme.html and place it in a Wiki?  I believe
there are probably enough of us using TileCache, that we could probably
contribute documentation to clarify and promote its use.

Regards,

Roger
--

On Tue, Nov 18, 2008 at 4:21 PM, Roger André <randre at gmail.com> wrote:

> Hi Christopher,
>
> Thanks for the advice, I'll give that (0,10) a shot.
>
> Any chance you can send me the link to, or the full-text of the
> conversation between Frank and Klokan?
>
> Roger
> --
>
>
> On Tue, Nov 18, 2008 at 4:17 PM, Christopher Schmidt <
> crschmidt at metacarta.com> wrote:
>
>> On Tue, Nov 18, 2008 at 04:07:19PM -0800, Roger André wrote:
>> > It's been pointed out that I didn't include a great deal of information
>> > about my setup.  I doubt it will matter much, but here goes:
>> >
>> > I am using TileCache to read a large (14400x7200) raster with global
>> > extents.  The raster projection is in lat/lon WGS84.  TileCache is set
>> to
>> > read this data via a MapServerLayer layer type, with settings that match
>> the
>> > example in the out-of-the-box tilecache.cfg (metaTile=true,
>> metaSize=5,5,
>> > metaBuffer=10).
>>
>> set metaBuffer:0,10 and you may see your edge defects disappear to some
>> extent.
>>
>> Probably something like this is the problem:
>>
>> 11:55 < FrankW> The problem is that GDAL transforms the destination area
>> back to the source coordinate system by sampling a grid of points over
>> the region.
>> 11:55 < FrankW> But points right on the international date line might
>> transform two different ways.
>> 11:55 < FrankW> so the region selector is missing the last swath of
>> data.
>>
>>
>> In GDAL-land, you can use:
>>
>> 11:42 < FrankW> klokan:  Try adding "-wo SOURCE_EXTRA=120" to your
>> gdalwarp commandline without the quotes
>>
>>
>> But I don't know how to use that through MapServer.
>>
>> > I am using the following package versions in my stack, and they have all
>> > been built from source:
>> >
>> > gdal-1.5.2
>> > mapserver-5.2.0
>> > proj-4.6.1
>> > proj-datumgrid-1.4
>> > tilecache-2.04
>> > --
>> >
>> >
>> >
>> > On Tue, Nov 18, 2008 at 3:17 PM, Roger André <randre at gmail.com> wrote:
>> >
>> > > Ok, so now that I've gotten meta-tiling with edge buffering to work, I
>> seem
>> > > to be able to better control the missing pixel rows that were causing
>> > > horizontal stripes in my Google Map tiles.  Only now I have a huge gap
>> at
>> > > the international date line.  I also have a band of missing data at
>> the
>> > > extreme South edge of my tiles when I am past Zoom Level 5.  I can
>> probably
>> > > live with that, but since my data set is global, I find it interesting
>> that
>> > > it's getting cut off, and only on the South side.
>> > >
>> > > Anyone seen this before?
>> > > --
>> > >
>>
>> > _______________________________________________
>> > Tilecache mailing list
>> > Tilecache at openlayers.org
>> > http://openlayers.org/mailman/listinfo/tilecache
>>
>>
>> --
>> Christopher Schmidt
>> MetaCarta
>>
>
>
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