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Polygon Styling

Control how GeoJSON polygon layers are rendered — fill colour, extrusion (3D height), stroke, and labels.

Fill colour

Three colouring modes (same as point markers):

ModeDescription
ManualSingle colour for all polygons
From datasetMap a string field to colours per category
GradientMap a numeric field to a colour ramp

Fill opacity slider — 0% (fully transparent) to 100% (fully opaque).

Extrusion (3D height)

Extrude polygons upward to create 3D shapes.

ModeDescription
NonePolygons are flat on the ground
Fixed heightAll polygons extruded to the same height (0–2000 m)
From datasetHeight driven by a numeric attribute. Set min/max height range, optional overrides, and base height offset
tip

Extrude building footprints by their height attribute to create a quick 3D city model.

Stroke

  • Enable/disable toggle
  • Colour — stroke colour picker
  • Opacity — 0–100%
  • Width — stroke thickness
  • Style — solid, dashed, or dotted
  • Dash length — controls dash spacing (when dashed style is selected)

Labels

  • Enable/disable toggle
  • Field — which attribute to display as the label
  • Font size — text size

Performance with large polygon datasets

When a GeoJSON layer contains more than 3,000 polygon and line features combined, the platform automatically switches to a batched high-performance renderer. You do not need to do anything — the switch is transparent.

  • Clicking features, toggling visibility, and all styling options continue to work as normal
  • Changing the opacity slider on a very large layer may take a moment to apply
  • Scenario snapshots capture and restore batched layers correctly

See Performance with large datasets in the Layers Overview for full details.