Comment by 0x_rs

This is a trivial task for any good model provided with all the tools it needs, and excluding the time it takes to download it from swissALTI3D -- which is the source of the data (heightmap, surface map, subsurface, building 3D models with swissBUILDINGS3D) and is a pretty useful resource for lots of terrain work. Other countries have similar datasets from airborne LiDAR, it's just very well published in Switzerland's case. Most European countries have this data available at similar 0.5m resolutions but coverage may not be as good in some cases. Some individual US states also publish them.