[mapserver-users] Re: polygon border artifacts

[Sven Geggus]

Sven Geggus <lists at fuchsschwanzdomain.de> wrote:

> OK YFTR:
> 
> Rendering water from Overlapping polygons does work fine in mapserver
> 6.0.x using the "APPROXIMATION_SCALE=FULL" PROCESSING directive.
> 
> "FORMATOPTION GAMMA=0.7" does not seem to be needed but won't be
> available in version 6.0.x anyway.
> 
> My problem was mith the specification of multiple PROCESSING
> directives.
> 
> The following syntax does not work, but does not result in a mapfile
> parser error either:
> PROCESSING "DIRECTIVE1=value1 DIRECTIVE2=value2"
> 
> Instead the following must be used:
> PROCESSING "DIRECTIVE1=value1"
> PROCESSING "DIRECTIVE2=value2"
> 
> In my case these are:
> PROCESSING "CLOSE_CONNECTION=DEFER"
> PROCESSING "APPROXIMATION_SCALE=FULL"

Oh well, here comes another FTR posting as this is only true with
OUTLINECOLOR and "WIDTH 0" specified which does produce other strange
artifacts in small zoomlevels.

When OUTLINECOLOR and WIDTH are omitted the border artifacts are back.

So here is the solution which is producing the desired results:

* Use mapserver from git master (6.1-dev)
* Render ocean polygons using a mapfile like the following:

--cut--
MAP

  OUTPUTFORMAT
      NAME agg
      DRIVER AGG/PNG8
      FORMATOPTION "INTERLACE=OFF"
      FORMATOPTION "GAMMA=0.6"
      MIMETYPE "image/png"
  END
  
  WEB
      METADATA
        "ows_enable_request" "*"
         wms_srs "EPSG:4326 EPSG:3857"
      END
  END
  
  PROJECTION
  "init=epsg:3857"
  END
    
  LAYER
     DEBUG 9
     PROCESSING "CLOSE_CONNECTION=DEFER"
     PROCESSING	"APPROXIMATION_SCALE=FULL"
     NAME           "ocean"
     TYPE           POLYGON
     STATUS         ON
     DATA           "ocean-120328"
     PROJECTION
        "init=epsg:3857"
     END
     CLASS 
       STYLE 
         COLOR "#579ae3"
       END
     END # of class
  END # of layer

END
--cut--



Sven

-- 
"The only thing we have to fear is fear itself" (Franklin D. Roosevelt)


/me is giggls at ircnet, http://sven.gegg.us/ on the Web