OpenStreetMap
This program can generate 3D terrain, buildings and trees from flat OpenStreetMap and SRTM (height) data, anywhere in the world. It uses everything the data offers to build something you can navigate in a walkable environment. Anything the data doesn’t offer, the software tries to ‘guess’ with various strategies.
PostgreSQL was used to store the data and was used for queries. A dedicated OpenStreetMap server was created to render and cache the tiled images (the temporary bitmaps on the ground):
A 3D view of OpenStreetMap
A close-up view of a generated 3D building
Roofs are generated using a dedicated spline-based algorithm. Even the tiles on roofs have shaders (special effects), along with Bump and Height maps to make them look 3D:
Pixel (fragment) and vertex shaders in action, creating tiles that look more than ‘flat’
It was even possible to open doors, walk in buildings, and go up via stairs to other floors, if more than one floor was generated. You could even get into loft spaces!
Note that this software was written for a previous employer, which means I do not hold the licence, and cannot sell it myself.