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<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=383250520-10092008>Roger,
</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=383250520-10092008></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=383250520-10092008>At
least at version 5.2, there is CLASS level OPACITY when you use the AGG image
format. For example, if I want to turn some of my polygons 50% opaque
(transparent), I can set an expression in one of the classes and set an OPACITY
for that class. I have pasted an example with Minnesota counties at the
end of this message.</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=383250520-10092008></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=383250520-10092008>I am
not sure if this is what you really want. I am guessing that you just want
to have an expression in one or more classes that tells MapServer which states
you want to not be colored. For that class, set an OUTLINECOLOR and not a
COLOR. For the other classes, set both an OUTLINECOLR and COLOR.
</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=383250520-10092008></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=383250520-10092008>David.</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=383250520-10092008></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=383250520-10092008></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=383250520-10092008>LAYER<BR> NAME "counties"<BR> STATUS
DEFAULT<BR> DATA "bdry_counpy2"<BR> TYPE POLYGON<BR> CLASSITEM
"CTY_NAME"<BR> CLASS<BR> NAME 'County
Boundary'<BR> EXPRESSION /^A/<BR>
#EXPRESSION "Aitkin"<BR>
STYLE<BR> COLOR 255 0
0<BR> OUTLINECOLOR 0 0
0<BR> OPACITY 50<BR>
END<BR> END<BR> CLASS<BR> NAME 'County
Boundary'<BR> STYLE<BR> COLOR
255 0 0<BR> OUTLINECOLOR 0 0
0<BR> END<BR> END<BR>END</SPAN></FONT></DIV>
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<DIV></DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT
face=Tahoma size=2>-----Original Message-----<BR><B>From:</B>
mapserver-users-bounces@lists.osgeo.org
[mailto:mapserver-users-bounces@lists.osgeo.org] <B>On Behalf Of </B>Roger
André<BR><B>Sent:</B> Wednesday, September 10, 2008 2:57 PM<BR><B>To:</B>
mapserver-users@lists.osgeo.org<BR><B>Subject:</B> [mapserver-users] Can a
CLASS be transparent?<BR><BR></FONT></DIV>
<DIV dir=ltr>Hi Everyone,<BR><BR>I'm new to the list and am not sure if this
has been properly answered already. The old posts that I have found all
seem slightly different regarding this topic, so I thought it would be safest
to ask again.<BR><BR>Is it possible to set a CLASS to be transparent?
The use-case being that I would like to put a raster layer underneath a layer
of US states, and selectively expose the rasters by making specific states
transparent. I suppose that I could write a CLASS expression for each
state, and simply omit an entry for each state that I want exposed, but I
wonder if there is a better way?<BR><BR>Thanks in advance for any suggestions
you can give.<BR><BR>Roger<BR>--<BR></DIV></BLOCKQUOTE></BODY></HTML>