Yves,<div><br></div><div>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..</div>
<div><br></div><div>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...</div>
<div><br></div><div> -Josh<br><br><div class="gmail_quote">On Wed, Nov 26, 2008 at 6:37 AM, Yves Moisan <span dir="ltr"><<a href="mailto:yves.moisan@boreal-is.com">yves.moisan@boreal-is.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="Ih2E3d"><br>
> maybe the right question would be: And how many overlay layers do you<br>
> have Yves?<br>
><br>
> I remember one OL user was complaining about speed, and he had like 80<br>
> layers :D Keeping it under 3 layers at a time should do the trick i<br>
> think.<br>
<br>
</div>Well indeed that's an issue. I have 20 some overlays. I know it's too<br>
much and a lot of those layers could be turned into composite layers<br>
e.g. all line feeatures could be grouped in one layer with symbology,<br>
but that means using a custom LayerSwitcher.<br>
<div class="Ih2E3d"><br>
> People should take more care with number of layers. Instead of<br>
> piling up the layers, one should group layers in wms request: you<br>
> loose some speed on rendering it, but if you use caching its well<br>
> worth it ;)<br>
<br>
</div>The overlays are not cached. I'm supposed to have a script that bundles<br>
calls to MapServer somewhere. If you have pointers, I'll take them.<br>
<br>
Thanx,<br>
<font color="#888888"><br>
Yves<br>
</font><div><div></div><div class="Wj3C7c"><br>
<br>
<br>
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