Commercial scanners are used to create as-built models from range data. One example is an Atlas launch tower was scanned from several locations, all images were inter-registered, and a model was produced for renovation . The areas scanned were difficult to reach, apparently, as the scanning hardware was held hundreds of feet off the ground by a crane. Another example of acquiring as-built models is that of sets for Hollywood movies . The Cyrax scanner was used to scan a cave set from the movie ``Starship Troopers.'' 3D CAD models were produced, which allowed computer graphics artists to superimpose animations in the proper locations.