Styling polygon dash-dot borders in GeoServer using SLD

Question

I want to draw polygon borders using a pattern of dashes and other symbols like triangles or circles but most polygons share borders so I get an undesired result.

Using this SLD code:

  <se:PolygonSymbolizer>
    <se:Fill>
      <se:SvgParameter name="fill">#cf72be</se:SvgParameter>
    </se:Fill>
  </se:PolygonSymbolizer>
  <se:LineSymbolizer>
    <se:Stroke>
      <se:GraphicStroke>
        <se:Graphic>
          <se:Mark>
            <se:WellKnownName>circle</se:WellKnownName>
            <se:Fill>
              <se:SvgParameter name="fill">#333333</se:SvgParameter>
            </se:Fill>
          </se:Mark>
          <se:Size>6</se:Size>
        </se:Graphic>
      </se:GraphicStroke>
      <se:SvgParameter name="stroke-dasharray">6 18</se:SvgParameter>
    </se:Stroke>
  </se:LineSymbolizer>
  <se:LineSymbolizer>
    <se:Stroke>
      <se:SvgParameter name="stroke">#AA0000</se:SvgParameter>
      <se:SvgParameter name="stroke-dasharray">10 14</se:SvgParameter>
      <se:SvgParameter name="stroke-dashoffset">14</se:SvgParameter>
    </se:Stroke>
  </se:LineSymbolizer>

I get this result in GeoServer:

Is there any way to avoid having two overlapping border lines or to make symbols perfectly overlap?

Most reliable work flow is to convert polygons into linestrings, remove duplicate line segments from the shared borders and use this cleaned linestring dataset for symbolizing the outline. — user30184, Oct 26 '17 at 09:26
I was looking for a solution other than what you suggest, but thank you anyway. — DMS02, Oct 27 '17 at 10:30
You deal with an old problem and I fear that you can't find a new magic solution. The two other alternatives that I know of are listed in https://gis.stackexchange.com/questions/171182/how-to-make-dashed-lines-between-adjacent-polygons-render-correctly-in-qgis. — user30184, Oct 27 '17 at 10:38

score 1 · Answer 1 · answered Nov 02 '17 at 08:43

Agree with the other comments, it's a matter of pre-processing the data to extract the linework and remove the duplicates, then paint the linework in a FeatureTypeStyle above the fill one to avoid fill overlapping with the circles in the border.

Now, it would also be possible to do this on the fly in a Rendering Transformation, assuming there are scale dependencies avoiding to load everything into memory. This RT would have to be written of course, if you are interested see: https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer

Styling polygon dash-dot borders in GeoServer using SLD

1 Answers1