[Mapserver-users] alpha blending

Paul Spencer spencer at dmsolutions.ca
Tue May 11 11:34:09 EDT 2004

There is a 'transparency' attribute on layer objects that controls 
transparency for the whole layer.  What isn't possible is to create 
classes/styles that have transparency on individual features.  That 
would have to be done by creating multiple layers with different 


bartvde at xs4all.nl wrote:
> Hi list,
> what are the current alpha blending capabilities of Mapserver?
> I saw an e-mail from Frank Warmerdam from 2002 in which he states:
> "I would like to see Map file color keywords be able to specify an RGBA
> color, instead of just RGB but even then alpha blending can only practically
> be done on 24bit output, not colormap output files."
> But AFAIK nothing has been pursued in this direction. The current state of
> GD would make this possible.
> So my impression is that alpha blending is only possible for raster layers
> at the moment and not for vector layers. Is this impression correct? Are
> there any plans to support the RGBA colors in the MAP file?
> Best regards,
> Bart
> _______________________________________________
> Mapserver-users mailing list
> Mapserver-users at lists.gis.umn.edu
> http://lists.gis.umn.edu/mailman/listinfo/mapserver-users

|Paul Spencer                           pspencer at dmsolutions.ca   |
|Applications & Software Development                              |
|DM Solutions Group Inc                 http://www.dmsolutions.ca/|

More information about the mapserver-users mailing list