Irrlicht Engine

Which one to choose? Newton seems natural choice, mostly due to few wrappers available (IrrNewt, IPhysics) but lacks support for vehicles other than rear wheel drive - well, it might be worked around but I don't really feel like doing such hacks..

Check out this site: http://srtm.csi.cgiar.org/Index.asp . Using Google Earth and one of two KMZ files hosted there you can get all the data you need. Then you just have to make an image out of it.

The latest available IPhysics (1.2) works with Irrlicht 1.4.2, although few code fixes are necessary. To make it work with VC2008 I also had to rebuild IPhysics.dll.