ARLINGTON, Va. -- An AFRL-funded research team at the University of California at Berkeley devised a novel methodology for building three-dimensional (3-D) models of urban environments in a fast, scalable, and automated way. The scans provide photorealistic renderings that enable virtual walk-, drive-, and fly-throughs. The new approach involves creating a digital surface model out of airborne laser scans (with complementary roof and terrain shape) and texture-mapping the scans with aerial imagery.

The availability of 3-D models representing major metropolitan areas allows the Air Force to execute its missions--both domestic and international--with more efficiency and precision. Having the exact 3-D map of a city is useful in counterterrorism activities, mission planning, and disaster management. 

Previous 3-D modeling methods required that data acquisition (i.e., scanning) equipment be parked near a particular object (i.e., building or structure) for an extended period of time. The new technology's continuous-mode scanning capability cuts this acquisition window to approximately 25 minutes. The end result is a detailed model of the building or structure.

The new 3-D modeling approach permits automated generation of textured 3-D city models that supply both high-level detail at ground level and low-detail, complete coverage of aerial views. Acquiring a close-range facade model at ground level is as simple as driving a vehicle equipped with laser scanners and digital cameras through a downtown area under normal traffic conditions. Negotiating the street in a continuous--rather than stop-and-go--fashion affords extremely fast data acquisition times.

Following completion and transition of the ongoing 3-D modeling effort, the team would like to extend its work to the indoor environment and consider the problem of incremental model updating after a building has been demolished. The researchers would also like to examine the suburban landscape, where trees and other natural objects are intermingled with buildings.

Keywords for search: 3-D, urban environments, walk-throughs, fly-throughs, video and image processing, algorithms, counterterrorism, mission planning, disaster management, detailed ground-based model, acquisition apparatus, surveillance.