[Tilecache] Quick panning with overlays

[Yves Moisan]

> 
> I think 20 overlays is .. a lot.  especially from a dynamic WMS - must
> take a while to render, forget panning!  Instead of grouping them in
> OpenLayers (which would still mean 20 OL layers), can you group them
> in the WMS -- that helps with things like labeling as well..

Hey Josh,

Indeed I have 20 some odd overlays and 3 base layers.  Those 3 layers
are Google hybrid, a blank 1 X 1 gif to act as no base layer and an
Ikonos image which I've massaged with gdal as per
http://ms.gis.umn.edu/docs/howto/raster_data ch. 10 and which I
eventually used TC on mod_python for.  None of the overlays are
Tilecached because they're a bunch of very small shapefiles.  Grouping
in the WMS means that I need to tweak my mapfile right ?  I tried
looking for examples on the MapServer site and didn't find anything.  Or
is that grouping done elsewhere ?

> 
> As for caching, I assume something like TileCache was meant.  I think
> I actually saw a patch to tilecache recently that lets you do a form
> of 'cascaded wms' (eg merging of wms layers) in tilecache itself for
> that matter...

I guess that applies for TileCached layers only, which isn't my case.

Thanx !

Yves