Lumbini, Mon 18 Mar 2024

Swisstopo Building Simplification

The printed maps of Swisstopo display buildings at scales of up to 1:200'000. Normally, buildings would be barely visible at this scale. Consider for example a building with side length 20 m. It would be only 0.1 mm wide on a 1:200'000 map. The printed maps therefore need a technique of building simplification.

The building simplification used by Swisstopo seems to group multiple buildings into one new building with a generic, near rectangular shape. The orientation of this uber-building seems to follow roughly the orientation of the original buildings.

Below you find an example:

Swisstopo maps of Triengen at scales 1:200'000, 1:100'000,1:50'000, and 1:25'000 from top to bottom. Note how multiple buildings are grouped into a single black square at each zoom step.

It might be possible to apply a similar technique to building simplification in vector tiles.