Even from scratch or from dgn/dxf vectorial format’s contour lines you create your own scenario.
Then import your model previously created using Sketch-up (this time i used google’s 3d warehouse, thank you Dilbert).
Stamp your house using sketch-up sandbox tools.
Then fur your scenario as if it was grass…
A little of photoshop like clouds and thats it!
Alberto C.
geographer, 3d designer & 3D GIS technician
Geovisualization.net 