Looking forward to the release of PlaceMaker as a long time OpenStreetMap contributor and since I wrote a 2D only OpenStreetMap importer for Sketchup called skp2osm back in 2011.
As already mentioned, the PlaceMaker sources data form OpenStreetMap, a global wiki-like map.
So everyone can contribute to the quality of the underlying OpenStreetMap data by mapping 3D features like height and type of the roof for a building. A good introduction to mapping 3D features in OSM is here. Post any question about 3D mapping in OpenStreetMap here.