Edit Polygon Features

Polygon editing is used for boundaries, service areas, parcels, buildings, and other features where the shape itself carries operational meaning.

Polygon draft snapping to the border of an adjacent polygon

Create a polygon feature

1. Open Edit Layer and choose the polygon layer.
2. Choose Create Feature and select Start.
3. Click around the boundary to place each vertex, usually by following a real footprint or operational boundary already visible in the project.
4. Complete the outer shape. Use Add part for multipart features and Add ring for interior holes.
5. Inspect any shared edge closely, then save the polygon.

Important — close the edit session to rebuild tiles. Hot deltas appear immediately on the map, but PMTiles, selection index, cluster, and hexbin artifacts rebuild when you Close session. Closing the edit panel (X) does not end the session.

Edit an existing polygon

Existing polygon selected for editing with loaded attributes

1. Open Edit Layer and choose the polygon layer.
2. Choose Edit Feature.
3. Select the polygon you want to revise.
4. Adjust the boundary while preserving the intended operational shape.
5. Review the updated geometry carefully if the polygon is shared with nearby context.
6. Save the change.

Why polygon editing needs more care

Polygon changes can affect neighboring context and downstream analysis much more visibly than many point edits, especially when boundaries are shared or interpreted operationally.

Common errors

• Geometry rejected — retrace the shared border and confirm snap targets before saving. See Snapping and Shared Borders.
• Map looks stale after save — confirm you are still in an open edit session; close the session to rebuild base tiles.
• Slivers or overlaps — pause before save and inspect the shared edge at a high zoom.

FAQ

Why didn't the map update after I saved?
Saves write hot deltas immediately. Base PMTiles and rollups update after you close the edit session.

Should I use Add ring or Add part?
Use Add part for disconnected areas of the same feature. Use Add ring for holes inside an outer ring.

Next steps

1. Snapping and Shared Borders
2. Edit Session and Tile Rebuild
3. Spatial Selection