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Land-Use Planning By Joystick

Scottsdale planners fly decision-makers through potential developments.

Virtual reality may be replacing static renderings, photographs and map symbols as the medium for presenting land-use proposals in Scottsdale, Ariz. The city council, planning commission and general public have apparently had it with trying to visualize proposals based on lay interpretations of maps and static images. Confirmed believers in leading-edge technology, Scottsdale council members put the problem to the staff of the city's Advanced Technology Program (ATP).

With funding from the council and NASA to acquire satellite and airborne imagery, ATP staff assembled a team from industry to devise a system for adding three-dimensional (3-D) geographic information and computer modeling to GIS. Within a matter of months, the team came up with a prototype system that "flies" observers through 3-D digital terrain imagery and computer-generated models in realtime. Users can zoom in, pull back, show scenes from any perspective, and change features on the fly to create "what-if" scenarios. Even better, they can visualize the appearance of proposed developments and designs.

ATP Manager Ray Miller said there is no interpretation on the user's part. "The visualization is a representation that lets decision-makers focus on the issues, not the data."

A user-development team of city planners and ATP staff recently demonstrated the prototype system for the city council and general public using actual cases in land acquisition, general planning, zoning and design. Considering the council's response, the demonstration clearly validated the potential of the system to improve the quality of information used to make decisions affecting land use.

PROVIDING THE SOLUTION
Scottsdale has long been a strong supporter of innovation and leadership in technology. Geographic information, for example, is the core data system for all city operations, with OLE-compliant GIS distributed to 200 desktop computers. All 1,500 of the city's desktops are connected and linked to the Internet through a fiber-optic asynchronous transfer mode network. The network was installed to handle visual data and provide fast access to multi-protocol networks.

Prior to 1997, graphics used in land-use proposal presentations consisted mainly of maps and geographic data, static renderings and orthophotography. Miller pointed out, however, that most council members and the general public have difficulty interpreting such data. "They haven't a clue as to what green, red and blue lines and polygons and points mean. As a result, a lot of the decision process is taken up just understanding the context of the information, before ever getting to the issues."

Scottsdale Chief Information Officer Greg Larson agreed. "Planning commissions, city councils and the general public find it much easier to have complex information presented in the most realistic fashion possible. That can be done by presenting geographic information in 3-D."

By January 1997, the team was ready to demonstrate the prototype to the city council. In the main conference room, they installed three large, concave screens and three separate Proxima high-resolution data projectors with input from separate computers. The computers were linked by remote access, providing control of multiple machines from a single keyboard and mouse.

The three-screen design enables viewers to focus on the main geographic image or model without having to simultaneously interpret superimposed alpha numerics. The left screen displays a menu the operator can access to bring up requested data or thematic maps, run queries or edit text related to the presentation. The right screen functions as a reference, displaying geographic information and data related to the imagery on the middle screen. "The system is oriented toward and defined by users and decision-makers," said Miller. "We can modify the software or the visuals to suit their needs."

The middle screen displays "fly-thrus" of digital 3-D terrain and computer-generated models. A joystick controls speed and direction of movement.

REAL-WORLD DEMONSTRATION
To demonstrate the capabilities of the system, a user-development team of planning directors and ATP staff assembled projects representing different planning processes -- land acquisition, general plan policy, zoning and design -- that required decisions
by the City Council and Planning Commission.

The demonstration for land acquisition and general plan policy included a presentation of the McDowell Sonoran Preserve, an environmentally-sensitive mountainous area of 25 square miles within the city limits. Scottsdale is in the process of acquiring the land as a recreation and wildlife preserve. Using a 3-D digital terrain model of the area and thematic layers from the GIS, the team presented walk-thrus and fly-thrus of the preserve to show the character of the area -- what one would see walking along certain trails, the locations of public access points, their appearance, and what could be seen 360 degrees from certain locations. The preserve was shown from both ground level and altitude, and from different perspectives in the city. If a council member wanted to go in a certain direction, the operator simply moved the joystick. On the right screen was a boundary superimposed over an aerial photo and a moving blip to show the path being taken.

To test the accuracy of the technology in predicting the appearance of potential projects, the team built a computer model of a development as proposed in 1991, and compared it with orthophotos and 3-D digital photographs of the site as it looks today. Instead of using actual building designs in the model, the team used blocks reflective of structure size and zoning. The middle screen displayed various aerial views of the model with the mountains in the background, and street-level views from within the development. The right screen displayed the 3-D digital photographs of the development as it looks today.

Juxtaposing the model with photographs of the development today demonstrated the accuracy of the system in visualizing how a project or development might look, even at the zoning stage. "The effect was very powerful," said Larson. "With the model next to the photograph of the completed project, you could see how they were reflective of each other."

For a demonstration on design review, ATP staff worked closely with the redevelopment agency on a computer-generated model of the downtown waterfront project. Scottsdale is planning to develop a walk with a "San Antonio look and feel" along the city's canal. Using photographs of the canal today (taken with Casio and Kodak digital cameras) and adding images and objects from architectural drawings, the staff built a computer-generated model of what the canal walk might look like with cafes, shops and people.

Where infrastructure had not yet been designed, the staff made drawings or used images from the computer library to show bridges, railings, tiles, and light fixtures. They created design changes to show the effects, including day and night settings to see how light fixtures appeared. With continued advances in the prototype, ATP will soon be able to take council members for a virtual stroll through the canal walk model.

"ATP clearly demonstrated that the addition of visualization and modeling tools to GIS has the potential for improving the way local government makes decisions affecting land use," said Larson. "Furthermore, as visualized 3-D geographic information evolves to a true desktop application, we believe GIS will become the enterprise-wide data solution for local government throughout the next century."

As for the council's response to the overall presentation, Miller said, "They gave us a standing ovation."

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SOLUTION SUMMARY
PROBLEM/SITUATION: Difficulty presenting proposed land-use changes to decision-makers.

SOLUTION: 3-D visualization and modeling tools.

JURISDICTION: City of Scottsdale, Arizona.

VENDORS: Intergraph, CG2, JAYA Corp., Casio, Kodak, ArcInfo, MapInfo, MicroStation.

CONTACTS: Ray Miller, 602/994-2744; Wil Orr, 602/994-7832; Mark Ledbetter, 602/994-7766.




Recognizing the need for greater visualization of proposed developments and construction plans, the Scottsdale city council, in July 1996, funded an Information Systems proposal to simulate and project 3-D visualization and computer-generated models in static and realtime modes. With $550,000 from the council and additional funding from NASA, ATP brought together a design team from CG2, JAYA, and Intergraph to develop a prototype. Initially, these firms had all the pieces needed for the system. It remained for them to integrate the different technologies.

The software component from Intergraph was GeoMedia, a recently introduced desktop GIS designed to integrate into and query all types of databases without translating graphics or tabular data. GeoMedia is also packaged as an OLE server, which allows users to design their own interface. The visualization hardware is an Intergraph graphics card with a geometry accelerator for displaying topology and capable of supporting 64MB of texture memory.

"The reason we chose the GeoMedia product," says ATP Modeling Projects Coordinator Hoyt Johnson, "is because it is the only commercial product out there, to my knowledge, that will allow me to bring in data from ArcInfo, MapInfo, MicroStation or other Intergraph data and do analysis between those different formats without having to translate all of them into some single format."

CG2 interfaced 3-D visualization with Intergraph's GeoMedia, a process that included writing code to maximize performance of the graphics hardware. "We are running large textured data and a lot of polygons with very accurate topology into the system," Miller said, "and still getting 30 frames per second out of it. That's CG2's expertise."

CG2 and JAYA designed an interface to take 2-D spatial information from GeoMedia through the user's query and extract 3-D representation. JAYA wrote the software for integrating the whole application and created an interface for analysis. To make the application available to the widest number of users, the system was designed to run on a desktop PC. The prototype was demonstrated on powerful Intergraph platforms, customized to accommodate the need for high graphics-processing speed and disk space.

Imagery and motion were generated by the prototype system running on an Intergraph TDZ 610, with four 200MHz processors, 512MB of RAM and 64MB of texture memory. Software used in demonstrating the prototype system included Modular GIS Environment Terrain Analyst and Advanced Imager for processing computer-generated models. An Intergraph TDZ 400 running GeoMedia and Model View is used to generate digital photographs, renderings, and maps on the right screen. These machines are Intel-based and running under Windows NT.