Processing and geoprocessing tools

The Processing panel brings a vector toolbox and terrain analysis to the map, so GIS-capable users can run common geoprocessing without a round trip to desktop GIS. Open it from the Processing entry on the ribbon while editing a map.

Every tool runs in the browser - the geometry work is done by an in-browser DuckDB spatial engine, and terrain analysis reads only the DEM sources the map already streams. Nothing is sent to a processing service.

The Processing panel

The panel lists the available tools grouped by kind:

  • Geometry - buffer, centroid, convex hull, bounding box, dissolve, simplify.
  • Overlay - clip, intersection, union, difference.
  • Join - spatial join.
  • Terrain - contour lines (see below).

Pick a tool, choose the input layer (or layers) already on the map, fill in its parameters, and run it. You can cancel a running tool, and the panel reports how many features the result contains.

Tool reference

Tool Group What it does
Buffer Geometry Grows (or shrinks) features by a distance you set.
Centroid Geometry Reduces each feature to its centre point.
Convex hull Geometry The smallest convex polygon that contains the features.
Bounding box Geometry The axis-aligned rectangle around each feature.
Dissolve Geometry Merges features into one, optionally grouped by a field.
Simplify Geometry Reduces vertex detail while keeping topology.
Clip Overlay Keeps the parts of one layer that fall inside another.
Intersection Overlay The overlapping area of two layers, with attributes from both.
Union Overlay Combines two layers, splitting where they overlap.
Difference Overlay Removes the parts of one layer covered by another.
Spatial join Join Attaches attributes from one layer to another by location (intersects, within or contains).

Distance units and the working CRS

Tools that take a distance - buffer and the simplify tolerance - need to work in metres, not degrees. Icon Map automatically picks a suitable metric projection (a UTM zone chosen from the centre of your input) so distances behave correctly, and shows the working CRS it selected in the panel. The result is transformed back to the map's coordinate system afterwards.

Automatic UTM selection is designed for regional extents. When an input straddles the antimeridian or reaches into the polar regions, a single UTM zone can distort distances - Icon Map shows an accuracy warning in these cases so the result is never silently misleading.

Limits and honesty

  • Large inputs are flagged. If an input has more than 250,000 features, Icon Map asks you to confirm before running, because the operation may be slow.
  • Outputs are capped at 100,000 features. When a result would exceed the cap it is truncated to that size and a visible warning is shown, so you always know the result is partial - it is never silently cut.

Results become layers

A tool's result is added to the map as a new Shapes from file layer, ready to style, join and query like any other. The tool that produced it and the parameters you used are recorded on the layer as provenance, so you can always see how a derived layer was made. You can save the result to your OneLake as GeoJSON so it survives a reload; an unsaved result is a session-only layer.

Contour lines from terrain

The Terrain group includes Contour lines, which derives elevation contours from the DEM (digital elevation model) the map is already using for its 3D terrain - falling back to the hillshade layer's DEM if terrain isn't set. This works with any of the supported DEM sources: Mapterhorn (the default), a custom terrain URL, a DEM stored in OneLake, an ArcGIS elevation service, or a greyscale-relief source.

Contours are generated across the current view, with these controls:

  • Interval - the vertical spacing between lines, in metres.
  • Major lines - mark every Nth line as a major (index) contour for emphasis and labelling.
  • Smoothing - smooth the lines for a cleaner cartographic look.

Detail automatically fits within a tile budget for the extent. If the requested detail would exceed the budget, Icon Map reduces the detail and warns you rather than returning a partial result. Areas with no elevation data are clipped out honestly, so contours never invent values across gaps in the DEM.

The result is a shapes layer with an elevation value on each line - style it, and use labels placed along the lines to annotate heights.

Availability

Processing is an authoring aid: the panel is available while editing a map and is not shown in the published viewer. The result layers it produces, however, are ordinary layers and appear in published maps like any other.

Next steps