About SLD Support

You can interpret styling from an SLD (Styled Layer Descriptor) file. You can use such an SDL file to express vector styling for prepared datasets.

Below are listed the current supported styling possibilities that can be specified through an SLD file (with a .sld extension). For more information on the SLD standard definition, which is based on the SE (Symbology Encoding) standard, see:

Important:
  • SLD support applies to rendering capabilities only.
  • Some capabilities in City experiences cannot be specified or modified through SLD.
  • Only a single SLD file per datasource document is supported; therefore the first SLD file that is found in the datasource document applies to the dataset.

This page discusses:

See Also
About Datasets
Creating and Updating Datasets

Symbolizers

Graphic symbology can be used in different contexts through the Graphic tag. For instance, you can used it to display symbols at points, or to fill polygons with textures.

Colors should be defined as RGB hexadecimals, preceded by a #. For example, #FF000 corresponds to the red color.

Length and distances are interpreted in pixels.

Important:
  • Multipass symbolizers are not supported. This means that you cannot define more than one geometry symbolizer for a single rendering, or one TextSymbolizer for the same set of features.
  • Each symbolizer must be used with the appropriate geometry type: PolygonSymbolizer must be used for polygons, not for lines or points, PointSymbolizer must be used for points, etc.

You can use the following tags:

PointSymbolizer

PolygonSymbolizer lets you define symbols at points using a Graphic tag.

This tag can contain a Mark or ExternalGraphic tag.

Mark

Mark lets you set simple rendering attributes. Below is an example:

<PointSymbolizer> 
 <Graphic>
  <Mark>
   <Fill>
    <SvgParameter name="fill">#ff0000</SvgParameter>
   </Fill>
  </Mark>
 </Graphic>
</PointSymbolizer>

  • 'fill' represents a color and is used as the base color:

<CssParameter name="fill">#8C875B</CssParameter>

  • 'fill-opacity' represents a ratio of opacity for the surface of the represented geometry:

<SvgParameter name="fill-opacity">0.7</SvgParameter>

For POI billboard layers, the color and opacity are applied over the default graphic or user-defined icon.

ExternalGraphic

ExternalGraphic lets you define point billboard geometries. Each associated point displays the described graphic icon. Below is an example:

<PointSymbolizer> 
 <Graphic>
  <ExternalGraphic>
   <OnlineResource xlink:type="simple" xlink:href="sld_icons/LOCATION_01.png"/>
   <Format>image/png</Format>
  </ExternalGraphic>
  <AnchorPoint>
   <AnchorPointX>1.0</AnchorPointX>
    AnchorPointY>1.0</AnchorPointY>
  </AnchorPoint>
  <Displacement>
   <DisplacementX>0</DisplacementX>
   <DisplacementY>0</DisplacementY>
  </Displacement>
 </Graphic>
</PointSymbolizer>

Relative urls access the dataset’s source document as a root. It can access zipped hierarchies as in the example abovewhere sld_icons is a zipped folder.

Anchor Point

Represents the point that anchors to the scene. The anchorX and anchor Y parameters are a ratio of the graphic’s dimensions.

Displacement

Gives the possibility to offset in pixels the anchor point.

LineSymbolizer

LineSymbolizer defines styling for lines.

Below is an example:

<LineSymbolizer>
 <Stroke>
  <CssParameter name="stroke">#0000FF</CssParameter>
  <CssParameter name="stroke-width">3</CssParameter>
  <CssParameter name="stroke-opacity">1</CssParameter>
  <CssParameter name="stroke-dasharray">4 0.2 1.4 2</CssParameter>
 </Stroke>
</LineSymbolizer>

Stroke rendering parameters are used but note that Fill rendering parameters cannot be used to fill lines.

  • 'stroke' represents a color and is used as the color of the stroke
  • 'stroke-opacity' represents a ratio of opacity for the stroke of the associated geometry
  • 'stroke-width' represents the width of the related stroke
  • 'stroke-dasharray' is a list of float values representing a dashArray pattern.

PolygonSymbolizer

PolygonSymbolizer defines styling for polygons.

A polygon layer can display a filled surface and/or a stroke geometry. Below is an example:

<PolygonSymbolizer>
 <Fill>
  <CssParameter name="fill">#8C875B</CssParameter>
  <CssParameter name="fill-opacity">0.8</CssParameter>
 </Fill>
 <Stroke>
  <CssParameter name="stroke">#0000FF</CssParameter>
  <CssParameter name="stroke-width">44.35433</CssParameter>
  <CssParameter name="stroke-opacity">0.2</CssParameter>
  <CssParameter name="stroke-dasharray">4 0.2 1.4 2</CssParameter>
 </Stroke>
</PolygonSymbolizer>

where:

  • 'fill' represents a color and is used as the base color:

    <CssParameter name="fill">#8C875B</CssParameter>

  • 'fill-opacity' represents a ratio of opacity for the surface of the represented geometry:

    <SvgParameter name="fill-opacity">0.7</SvgParameter>

  • 'stroke' represents a color and is used as the color of the stroke
  • 'stroke-opacity' represents a ratio of opacity for the stroke of the associated geometry
  • 'stroke-width' represents the width of the related stroke
  • 'stroke-dasharray' is a list of float values representing a dashArray pattern.

The SvgParameter and CssParameter tags can be used to define the interior (fill) and border (stroke) of polygons.

PolygonSymbolizer can also contain a GraphicFill tag to use external graphics. Below is an example:

<PolygonSymbolizer>
 <Fill>
  <GraphicFill> 
   <Graphic>
    <ExternalGraphic>
     <OnlineResource xlink:type="simple" xlink:href="Points.png"/>
     <Format>image/png</Format>
    </ExternalGraphic>
   </Graphic>
  </GraphicFill>
 </Fill>
</PolygonSymbolizer>

Text Symbolizer

TextSymbolizer lets you define styling for text labels. Note that labels are always displayed in overlay mode.

The CssParameter tag can be used to define the font. Below is an example:

<TextSymbolizer>
 <Label>
  <PropertyName>TEXTSTRING</PropertyName>
 </Label>
 <Font>
  <CssParameter name="font-family">arial</CssParameter>
  <CssParameter name="font-size">12</CssParameter>
  <CssParameter name="font-style">normal</CssParameter>
  <CssParameter name="font-weight">bold</CssParameter>
 </Font>
 <LabelPlacement>
  <PointPlacement>
    <Displacement>
      <DisplacementX>-30</DisplacementX>
      <DisplacementY>-30</DisplacementY>
    </Displacement>
  </PointPlacement>
 </LabelPlacement>
 <Fill>
  <CssParameter name="fill">#000000</CssParameter>
 </Fill>
</TextSymbolizer>

The following tags can be used to define a TextSymbolizer:

  • Label

    It should contain a PropertyName referencing the label contents for each geometry.

  • Fill
    • 'fill' represents a color and is used as the base color:

      <CssParameter name="fill">#8C875B</CssParameter>

    • 'fill-opacity' represents a ratio of opacity for the surface of the represented geometry:

      <SvgParameter name="fill-opacity">0.7</SvgParameter>

  • Font

    The font parameters available for this tag are as follows:

    • font-family
    • font-style
    • font-weight
    • font-size
  • LabelPlacement

    Defines the label position. The following parameters are avalable:

    • PointPlacement
    • Displacement
    • Rotation

AnchorPoint is always the center of the label. The Displacement and Rotation tags can be used.

Filter Functions

Filters let you specify conditions.

For instance:

<Filter>
 <PropertyIsEqualTo>
  <PropertyName>TYPE</PropertyName>
  <Literal>1003</Literal>
 </PropertyIsEqualTo>
</Filter>

Important:
  • You cannot define attribute styling without filters.
  • To use a specific filter on an attribute, the attribute must be exposed when the dataset is created.

Several tags are available to define filters.

  • Logical operators to combine filter operators.
    • <And>
    • <Or>
  • Mathematical operators to perform arithmetic operations on numeric values.
    • <Add>
    • <Sub>
    • <Mul>
    • <Div>
  • Boolean operators to specify conditions using comparisons.
    • <PropertyIsEqualTo>
    • <PropertyIsNotEqualTo>
    • <PropertyIsLessThan>
    • <PropertyIsLessThanOrEqualTo>
    • <PropertyIsGreaterThan>
    • <PropertyIsGreaterThanOrEqualTo>
    • <PropertyIsBetween>
  • Property values to refer to the value of a given feature attribute.
    • <PropertyName>
  • Literals to specify fixed values.
    • <Literal>