Symbology

When data is contained in a feature layer you can change the way data is represented by symbolising feature layer. Digital Twin provides many different symbolisation methods, known as symbolise, for feature layers:

• Single colour—Draw all features in a layer with a consistent colour.
• Graduated colours—Show quantitative differences in feature values with a range of colours.
• Categorised colours—Apply a different colour to each category of features within the layer.
• 3D view — Extrude feature layer from ground by a height value. (This function is only available for polygon features)

Supported Geometry type	Basic properties
Polygon	Colour, Stroke type (Solid / None), Stroke colour, Stroke width
Line	Stroke colour, Stroke width
Point	Colour Size

Single Colour

Single colour symbology applies the same symbol to all features in a layer. This symbology is used for drawing a layer with only one category, such as county boundaries.

1. Select a feature layer in the data panel.
2. Open more options menu and click style.
3. Select Create new style.
4. Give the style a readable name.
5. In the Type field, choose Single.
6. According to the geometry setting:
   1. Polygon: choose the fill colour, stroke colour, stroke style and stroke width.
   2. Polyline: choose stroke colour and stroke width.
   3. Point: choose the fill colour and point size.
7. Click save to save the style and apply it to the feature layer.

Graduated Colours

Graduated colour symbology is used to show a quantitative difference between mapped features by varying the colour of symbols. Data is classified into ranges that are each assigned a different colour from a colour scheme to represent the range. For instance, if your classification scheme has five classes, five different symbol colours are assigned. The size of the symbols stays the same. Maps that vary in colour this way are usually called choropleth maps. Typically, you choose a continuous colour scheme to apply different shades of the same colour so that lighter shades match lower data values and darker shades match higher data values.

1. Select a feature layer in the data panel.
2. Open more options menu and click style.
3. Select Create new style.
4. Give the style a readable name.
5. In the Type field choose Graduated
6. For the colour pattern setting:
   1. Choose the numeric field for the data to be mapped from the Value drop-down menu.
   2. Choose the colour pattern from the Colour Ramp field.
   3. Classify the data using an appropriate classification method and number of classes.
7. According to the geometry setting:
   1. Polygon: choose stroke colour, stroke style and stroke width.
   2. Polyline: choose stroke width.
   3. Point: choose point size.
8. Click save to save the style and apply it to the feature layer.

Categorised colours

Categorised colours symbolize qualitative categories of values. Examples include habitat types, planning zones, voting preferences, and soil classifications. It can be based on one or more attribute fields in the dataset.

1. Select a feature layer in the data panel.
2. Open more options menu and click style.
3. Select Create new style.
4. Give the style a readable name.
5. In the Type field choose Categorised
6. For the colour pattern setting:
   1. Choose the category field for the data to be mapped from the Value drop-down menu.
   2. Choose the colour pattern from the Colour Ramp field.
7. According to the geometry setting:
   1. Polygon: choose stroke colour, stroke style and stroke width.
   2. Polyline: choose stroke width.
   3. Polyline: choose point size.
8. Click save to save the style and apply it to the feature layer.

3D View (Extruded Polygons)

3D view is designed to give polygon features another dimension and increase the information density by adding height value. This style is suitable for features with height field such as building footprint with height value to visualise the building outline.

1. Select a feature layer in the data panel.
2. Open more options menu and click style.
3. Select Create new style.
4. Complete the style setting for Single, Graduated or Categorised.
5. Tick the box of Show 3D View
6. Assign the name of height attribute to the Height attribute field
7. Extruded Height Factor is an optional setting to scale to height value
8. Click save to save the style and apply it to the feature layer.