Style a Layer with alpha transparency for cloudcover¶

• Remember to adjust WMSFormat in WMS to output 32bit PNG images:

 <WMSFormat name="image/png" format="image/png32"/>

This is the legend configuration for cloudcover with alpha transparency

  </Legend>
    <Legend name="cloudcover" type="colorRange">
    <palette index="0"   red="255"   green="255"   blue="255"  alpha="0"/> 
    <palette index="240" red="255" green="255"   blue="255"    alpha="255"/> 
  </Legend>

This is the style for cloudcover

<Style name="cloudcover">
   <Legend fixedclasses="true" tickround=".1">cloudcover</Legend>
    <Min>0.0</Min>
    <Max>8</Max>
    <ContourLine width="1" linecolor="#444444" textcolor="#444444" textformatting="%2.1f" classes="3"/>
     <ContourLine width="3" linecolor="#0000FF" textcolor="#444444" textformatting="%2.1f" classes="4"/>
     <ShadeInterval min="-1" max="2"    label="&lt;2"    fillcolor="#E6E6FF"/>
    <ShadeInterval min="2" max="4"    label="2-4"    fillcolor="#B3B3FF"/>
    <ShadeInterval min="4" max="6"    label="4-6"    fillcolor="#8080FF"/>
    <ShadeInterval min="6" max="8"    label="&gt;6"    fillcolor="#4C4CFF"/>
    <RenderMethod>nearest,bilinear,contour,contourbilinear,shaded</RenderMethod>
    <NameMapping name="nearest"        title="Alpha transparency" abstract="Visualize radar images with alpha transparency on a log scale"/>
    <NameMapping name="bilinear"        title="Alpha transparency smooth" abstract="Visualize radar images with alpha transparency on a log scale"/>
  </Style>

This is is the layer definition with cloudcover

  <Layer type="database">
    <Cache enabled="false"/>
    <Styles>cloudcover</Styles>
    <Dimension name="time" interval="P1D">time</Dimension>
    <Variable>hih_cld</Variable>
    <DataPostProc algorithm="ax+b" a="8" b="0" units="octa"/>
    <FilePath filter=".*\.nc$">http://opendap.nmdc.eu/knmi/thredds/dodsC/essence/run021/2D_daymean/hih_cld_021_2026-2100.nc</FilePath>
  </Layer>