[OpenLayers-Users] Overlay Issue

[Christopher Schmidt]

On Fri, Sep 14, 2007 at 09:41:47PM -0700, Paul Ramsey wrote:
> There's clearly something going on in OpenLayers behind the scene  
> that is making things work, since the layers end up lining up  
> correctly (the WMS parcels neatly line up along the Yahoo roads).  

Yes. This behavior will change in 2.5, with the addition of the
SphericalMercator options -- the WMS Layer currently has its 'reproject'
option set to 'true' by default, which will change to 'false'. (This is
because the reproject option breaks other things, so havig it on
unneccesarily is bad.) 

> Curiously, they lined up even when I accidentally set the SRS option  
> on the WMS to 4326 (initially I had it set to 3395, WGS84 Mercator).   

I had seen this but punted on it, thinking 3395 and 4326 were the same.
Since they're not, I bet yoru backend WMS was not projecting things
right. With 4326, the reproject will do client side vertical stretching
of the layers... with 3395, I have no clue what it would do :) 

> OpenLayers, so good it works even when you screw up.

My new quote of the day.

Regards,
-- 
Christopher Schmidt
MetaCarta