Bolsena Hacking Event 2010

These days i'm in Italy to visit the Bolsena Hacking Event 2010. A group of open source GIS developers meets every year to work on several projects. I'm here to work with GeoCat developers on a ArcGIS-GeoNetwork bridge extension. But in the meanwhile I have interesting discussions with and presentations of developers of GeoServer, MapBender, Deegree, GeoCouchDB, GeojQuery, OpenLayers, Inspire and Grass. Send me a message if you'd like to bring in a subject.

Rotation in SLD and Esri

In ArcMap you can rotate point symbols geopgraphic and arithmatic. SLD/Geoserver rotates features in only one direction (geographic). So to get the arithmatic rotation in GeoServer (based on a field value) you should multiply the Esri-direction by -1:

<sld:Rotation>
<ogc:Mul>
<ogc:PropertyName>RICHTING</ogc:PropertyName>
<ogc:Literal>-1</ogc:Literal>
</ogc:Mul>
</sld:Rotation>

* <ogc:Mul> is the multiply implementation of SLD (all functions)

To get geographic rotation you have to add 90 degrees.