I then take the height-map export into World Machine for erosion and splat mapping export. (Although I would not recommend it, for testing you can get a plugin for world machine called “UDK layers”. Eventually you will want to create your own extractor macro to get the maps you need but it’s good for a quick mock up.
Going off of what Brian said. After you make the stamp, if you don’t have mudbox, you could import the stamp as a texture into blender and use it as the map for a displacement modifier. Apply that, add a plane under your terrain that is the same size.(technically the origins needs to be in the same place) scuplt your terrain, go to the bake options and bake the hightmap to the plain. We