WMS - Reprojecting and losing transparency?

[Frank Warmerdam]

On 9/6/05, Peter Giencke <pgiencke at glc.org> wrote:
> Hi,
> 
> Am I right to assume that under in the following circumstance, a
> 'reprojected' wms layer will lose its transparency? I did some digging and
> couldn't find a straight answer...
> 
> Below is a parred down version of the mapfile I'm using; it becomes
> untransparent after the projection to UTM. Hopefully I'm wrong and there's a
> way to do this....

Peter,

I gather the problem you are running into is that the TRANSPARENT 40
keyword for the layer is being ignored, right?  Does this really work if
there is no reprojection?  Looking at the code, it seems that 
msDrawMap() completely skips msDrawLayer(), and calls 
msDrawWMSLayerLow() directly for WMS layers.  This means all the
msDrawLayer() code for handling layer level transparency is ignored.

I would suggest you submit a bug for the WMS client layer implementators
to address (Assefa and Daniel).  

PS. You have two ENDs at the end of your first PROJECTION block.
It took me quite a it of work to figure out why the mapfile didn't
seem to render anything!

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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and watch the world go round - Rush    | Geospatial Programmer for Rent