WMS, lines, and tile borders

[Tim Schaub]

Hi Erik-

Erik Heinz wrote:
> Hi,
> 
> when using MapServer as WMS server to display a layer of TYPE LINE in
> connection with a tile-based client (e.g. Google Maps) the lines are not
> continuous across tile borders. Apparently, round line caps are drawn which
> lead to gaps at the tile borders particularly at low angles.

If you want to get around this bug and can use a client like OpenLayers, 
there should soon be support for tile "gutters" (buffers around tiles 
that are not displayed.

You can see an example in my gutter sandbox:
http://dev.openlayers.org/sandbox/tschaub/gutter/examples/gutter.html

Other clients that do meta-tiling (requesting large tiles and slicing 
them up into smaller tiles) also get around this problem by discarding 
the tile edges.  ka-Map and TileCache are two such clients.

Don't think you'll have any luck getting around this in Google Maps.

Of course it would be nice to have this fixed at the source.  Until 
then, you can use an agile client.

Tim