Paul Everett posts a small demonstration showing how you are able to effectively combine the OSM importer data along side the DEM Earth data in Cinema 4D. Using the Tools4D DEM Earth plugin and the OSM Importer, Paul easily combines the two into one scene file.
This Short toturial shows you how easy it is to map Open streetmap data onto DEM Earth
I have to admit, my jaw dropped a bit watching this demonstration, the street data perfectly overlays on top of the digital terrain, and you can easily run through a section of landscape by scrubbing the offset, pretty great stuff.
The DEM Earth plugin for Cinema 4D allows you to easily generate digital elevation models in your scene, automatically downloading the data that it needs to build the model that you want, by simply providing a geographic location.
The OpenStreetMap Importer for Cinema 4D allows you to just drag and drop an openStreetMap file into the viewport and will work efficiently with large files, importing data sets up to 2 GB. To learn more about the OSM Importer and DEM Earth for Cinema 4D, check the CinemaPlugins site here.