Players in the Field
Major players in GIS include four key vendors: ESRI (www.esri.com), Intergraph (www.intergraph.com), MapInfo (www.mapinfo.com) and Autodesk (www.autodesk.com). There are also dozens of startups and many small companies in the business (for a sample, see www.urbansimulation.com). ESRI is a major mover, with close to $500 million in GIS — related sales a year, including animation and data collection tools within ESRI's basic toolset, ArcGIS. The company conducts a yearly user's group meeting, usually in the San Diego area, that is a who's-who of the GIS crowd; this year's confabulation drew more than 12,000 attendees. Autodesk seems especially well placed in the GIS area, since it has toolsets to cover either wide-area projects such as models of cities (including its Map and Civil Engineering tools) or detailed projects such as individual buildings (with its AutoCAD toolset) — and users can then generate characters and motion in those environments via Autodesk's popular 3ds max animation package (from its Discreet division). Whereas some companies are developing specialized software, others are adapting their basic software packages for GIS applications. SketchUp, for instance, is developing a plug-in for its easy-to-use software (www.sketchup.com) that allows interaction with ESRI's geographic information system product line.

A 3D scan of the overpass. © Reigl USA.

Art Reflects Reality: Creating Virtual Environments
Whereas it will sometimes suffice to use rough city models generated from photos (this is done by taking different aspect angles and stretching the 2D shapes of buildings into 3D), for many applications this isn't good enough. Using CAD drawings is one way to generate models of buildings. But what if no CAD drawings are available? GIS artists then use a familiar technique: they scan the objects. Entertainment animators have used scanning for years — for instance, by using a digitizer (a stylus attached to a base) or a laser scanner to mark points in 3D space on a small object such as an hourglass, which then translates into a 3D digital model with the proper software. But how do you digitize something like a football field? Or a freeway overpass?

What you need for that is an industrial-strength scanner, such as the Riegl 3D LMS Scanner series. A scanner of this type sends out millions of laser beams and forms a "point cloud" outline of an area such as a building or a roadway overpass; this is then translated into a basic 3D shape or wireframe of the object(s). An associated digital camera can capture textures that can then be applied to the object(s) to result in a photorealistic 3D representation. The 3D scanner (which is about the size of a loaf of bread) can be mounted on top of a vehicle, which can be driven around a large area or a complex building such as a cathedral in order to capture all the sides of the object. Whole city streets can be modeled this way, from 3D scanning systems mounted on vehicles or helicopters (UAVs (Unmanned Aerial Vehicles) have been used for scanning in dangerous urban areas).

A 3D animated representation of COVER going through a city. The bubble represents how it sends the Wi-Fi signal all around.

An Application of GIS and the New Internet: the COVER System
An interesting application of 3D GIS — merged with New Internet technology — is COVER (Collaboration Operations Vehicle for Emergency Response), a type of mobile command post that enables collaboration between different elements of a response team, such as military, law enforcement, firefighters and HAZMAT (HAZardous MATerials) technicians. COVER consists of a protected vehicle with an internal electronics suite that puts up a WI-FI "bubble" — a circular area several miles wide within which digital devices such as laptops or online PDAs can all be connected and can communicate with each other. Because COVER uses New Internet (IPv6) technology, it can "discover" relevant digital devices in any area it is entering — both the COVER base station and all the players (and sensors) within the bubble know where and who everyone is. A key aspect to enabling everyone to communicate is that everything must be digital — for incoming messages from outside of the bubble, COVER incorporates a "debabelizer," a box that accepts normal (analog) radio transmissions at one end and outputs digital (VoIP) transmissions at the other end; at present, firemen, policemen and military teams cannot talk to each other — their radios are generally incompatible, creating a Biblical "Tower of Babel" effect.