SLD Point Stacker


```type<?xml version="1.0" encoding="ISO-8859-1"?><StyledLayerDescriptor version="1.0.0"xsi:schemaLocation="http://www.opengis.net/sld StyledLayerDescriptor.xsd"xmlns="http://www.opengis.net/sld" xmlns:ogc="http://www.opengis.net/ogc"xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">  <NamedLayer>    <Name>g_stacker</Name>    <UserStyle>      <Title>Point Stacker</Title>      <Abstract>A sample style that aggregates points</Abstract>      <FeatureTypeStyle>        <Transformation>          <ogc:Function name="gs:PointStacker">            <ogc:Function name="parameter">              <ogc:Literal>data</ogc:Literal>            </ogc:Function>            <ogc:Function name="parameter">              <ogc:Literal>cellSize</ogc:Literal>              <ogc:Literal>50</ogc:Literal>            </ogc:Function>            <ogc:Function name="parameter">              <ogc:Literal>outputBBOX</ogc:Literal>              <ogc:Function name="env">                <ogc:Literal>wms_bbox</ogc:Literal>              </ogc:Function>            </ogc:Function>            <ogc:Function name="parameter">              <ogc:Literal>outputWidth</ogc:Literal>              <ogc:Function name="env">                <ogc:Literal>wms_width</ogc:Literal>              </ogc:Function>            </ogc:Function>            <ogc:Function name="parameter">              <ogc:Literal>outputHeight</ogc:Literal>              <ogc:Function name="env">                <ogc:Literal>wms_height</ogc:Literal>              </ogc:Function>            </ogc:Function>          </ogc:Function>        </Transformation>        <Rule>          <PointSymbolizer>            <Graphic>              <Mark>                <WellKnownName>circle</WellKnownName>                <Fill>                  <CssParameter name="fill">#0000FF</CssParameter>                  <CssParameter name="fill-opacity">0.5</CssParameter>                </Fill>              </Mark>              <Size><ogc:Mul><ogc:PropertyName>countunique</ogc:PropertyName><ogc:Literal>3</ogc:Literal></ogc:Mul></Size>            </Graphic>          </PointSymbolizer>          <TextSymbolizer>            <Label>              <ogc:PropertyName>countunique</ogc:PropertyName>            </Label>            <Font>              <CssParameter name="font-family">Arial</CssParameter>              <CssParameter name="font-size">12.0</CssParameter>              <CssParameter name="font-style">normal</CssParameter>              <CssParameter name="font-weight">normal</CssParameter>            </Font>            <LabelPlacement>              <PointPlacement>                <AnchorPoint>                  <AnchorPointX>                    <ogc:Literal>0.5</ogc:Literal>                  </AnchorPointX>                  <AnchorPointY>                    <ogc:Literal>0.5</ogc:Literal>                  </AnchorPointY>                </AnchorPoint>                <Rotation>                  <ogc:Literal>0.0</ogc:Literal>                </Rotation>              </PointPlacement>            </LabelPlacement>            <Halo>              <Radius>                <ogc:Literal>2</ogc:Literal>              </Radius>              <Fill>                <CssParameter name="fill">#FFFFFF</CssParameter>              </Fill>            </Halo>            <Fill>              <CssParameter name="fill">#000000</CssParameter>            </Fill>          </TextSymbolizer>        </Rule>      </FeatureTypeStyle>    </UserStyle>  </NamedLayer></StyledLayerDescriptor>```
> [GeoServer Integration: rendering transformations - GeoServer Training](https://docs.geoserver.geo-solutions.it/edu/en/wps/rendering_tx.html)
