San Jose, California
William Jepson and Scott Friedman
UCLA Urban Simulation Team
Los Angeles, California
The UCLA Urban Simulation Team (UST) is using state-of-the-art visual simulation technology to build a Virtual Los Angeles that is currently being used by city planners, designers, and community groups to visualize and evaluate proposed changes and new developments in the urban environment. This paper focuses on this technology "Urban Simulation" as an innovative tool for interactive city planning and consensus building. Specifically, this paper will be covering the evolving modeling methodology for efficiently creating, visualizing, and managing three-dimensional (3D) virtual urban environments, and the technology's current planning applications with the City of Los Angeles, California.
What is Urban Simulation?
Since the collective process of city planning began, we as urban planners, designers, investors, policy makers, or simply concerned citizens have been in search of an innovative method for experiencing the built environment before it's actually built. We have sought ways to effectively see and analyze the physical impacts of a development prior to construction or investment. We designers have experimented with colored maps and site plans, cardboard models, rich architectural renderings, photomontages, or a combination of these. However, none of these tools have served to be a complete, effective technique to convey the past, present, and future of a "place" to the wide array of diverse players in the planning process.
Now for a moment, imagine your city or simply your neighborhood as a virtual world where you can walk, drive, or fly safely anywhere, and experience your environment as it currently exists, as it existed ten years ago, or as it might look in the future after physical changes are made. Try removing existing buildings and replacing them with landscaped parks or new developments. Walk around or through these parks or developments and sense what they will be like. Add or remove street trees from your block to see the impact, or change the type and age of the foliage in your neighborhood. Query a database for information on the buildings or areas you come across.
All of this is possible using state-of-the-art visual simulation technology. Previously, the use of this technology has been primarily limited to the exclusive realm of military and aerospace applications. Now as the technology becomes more affordable, it becomes feasible for planners, designers, and community groups to use it to visualize and evaluate proposed changes and new developments in the urban environment.
The Urban Simulation Team at UCLA has adapted this visual simulation technology to develop an integrated environment for urban simulation. Using this unique computer simulation system and methodology, the Team is creating real-time virtual models of urban areas. These models, which are accurate to the level of the graffiti on the walls and signs in the windows, are being constructed by combining aerial photographs with street level imagery and three dimensional geometry to create realistic 3D visual simulation.1
The efficient methodologies developed by the Team, (from the standpoint of the amount of time and labor required to construct a model and the amount of computing time required to interactively render such large models), combined with a visual simulation system which has been specifically tailored for urban simulation, has resulted in an extremely efficient system devoted to high quality community and city visual simulation.2
The Virtual Los Angeles Project
The UCLA Urban Simulation Team is in the process of creating a virtual model of the entire Los Angeles basin. This area comprises well over 4,000 square miles. The model is extremely accurate and provides a level of visual feedback to the user, which allows the immediate recognition of the present location by visual identification.
The creation of the Virtual Los Angeles database is a long-term project. The objective is to build a virtual model, which can be used to help solve a multitude of urban design and planning-related problems. Using commercial off the shelf modelers, such as MultiGen, the UST is creating the database from city engineering maps, numerous site visits, and its own internally generated plant, tree and foliage libraries.
Rather than attempt to build one large model from scratch, the Team has defined a methodology, which allows multiple small models to be created and linked together. To date more than a dozen separate area models have been built, ranging in size from one to fifteen square miles. This approach allows the Team to work with various public and private entities that have an interest in studying specific areas of Los Angeles. The approach also allows our clients to commission models, which respond to their particular needs, while we extend our urban database. The methodologies, which the Team employs to build these models, have reached the level of cost efficiency where we consistently have a six to twelve month backlog of work. After creation, these individual high-resolution urban models are inserted into a large area terrain database, which is currently bordered by San Diego, Las Vegas and Santa Barbara.
The Urban Simulation Team is currently under contract from the City of Los Angeles to create virtual models of the Hollywood Boulevard and MacArthur Park areas that are each about 45 blocks in size. These models are built as part of the virtual Los Angeles Project so that they fit accurately into the existing City database.3 They are currently being used by the Mayorís Office and the Redevelopment Agency to analyze future developments in these communities.
An Efficient Methodology
The efficient methodology developed by the Urban Simulation Team can be divided into three areas: (1) the creation of an urban database using a real-time 3-D modeling package, coordinate data from the city, and photographic textures of the urban area; (2) the interactive visualization of the database using the Team's simulation system, the Urban Simulator (uSim); and (3) the management of an ever-growing virtual world database using the Virtual World Server.
Creation of Database. There are numerous steps involved in the creation of an urban database. First, information is obtained from the local city planning department, including geographic coordinates, accurate street addresses, and an accurate linear map of the city streets. Superimposed on these maps are aerial photographs, which provide building and area footprints, trees, and landscaping. Using the real-time 3D-modeling package MultiGen II Pro provided by MultiGen, Inc., the image is then extruded or pulled into three dimensions.
The next layer of simulation involves the capturing of photographic textures. This process is achieved by on-site visits for actual street photography of every building facade with a digital camera. Also, photographic textures of generic architectural / urban images are obtained from other sources where on-site visits are not possible. This collection of images are then pasted or "mapped" onto the 3D computer-modeled buildings in the virtual world. At this point, a 3D urban environment is created, and is ready to be visualized in real-time (optimized for rendering 30 or more frames per second) by the UST Urban Simulator.
Visualization. The UST Urban Simulator (uSim) was designed to respond to the unique requirements of the Urban Planning, Urban Design and Architecture professions. UST focused on creating a user interface for viewing and interacting with a 3D environment in a way that would be both intuitive and easy to use. The interface and simulation software currently runs on the entire line of Silicon Graphics equipment, O2, Octane and Onyx workstations, allowing extensive use of real-time texture mapping. The Silicon Graphics IRIS Performer Application Programming Interface (API) was used to develop the simulation software. The UST interface to the simulation uses the Motif/X-Windows standard, and includes a well-defined set of functions that most users find sufficient for loading and viewing models without additional programming effort. Nonetheless, the interface design allows the simulation to be easily customized to support a particular application.4
The Urban Simulator's visualization of the urban database clearly communicates a designer's vision and land-use guidelines in an empowering manner simply because it is interactive, intuitive, changeable, photo-realistic, and adaptable.
Managing a growing database. A large database that represents a metropolitan city such as Los Angeles would most likely require over a terabyte of data. As a result, the issue of growth management in a virtual database becomes an issue. At UCLA, the Urban Simulation Team is part of larger team led by Richard Muntz, Chair of the Chair of the Computer Science Department under an ongoing project (the Virtual World Data Server) sponsored by the National Science Foundation. The team is designing and building a high performance real-time virtual world/ synthetic environment database server (and clients). The database system is designed to efficiently store and retrieve large amounts (greater than one terabyte) of spatially distributed heterogeneous data. The server is designed to provide guaranteed quality of service at pre-specified levels for multiple concurrent real-time 3D interactive sessions. This is achieved while simultaneously enabling a dramatic increase in the size of the problem that can be handled on a single workstation.6
City Planning Applications
Using the Urban Simulation Team's unique computer simulation system and methodologies, virtual environments have been created for various real world planning projects. With the creation of a number of Los Angeles communities, including the Hollywood and Westwood districts, the UCLA Urban Simulation Team has successfully implemented this technology for interactive city planning and consensus building on a number of projects in the city. These projects have been commissioned by various groups, including local developers and the Los Angeles Mayorís Office.
Westwood Village Project. During the Summer of 1996, the Urban Simulation Team was commissioned by a local Developer, Ira Smedra to build a virtual database of a proposed mixed-use development, Westwood Village and the surrounding contextual neighborhood. This development is to be located in the heart of the Westwood district of Los Angeles near the UCLA campus, and includes a residential high-rise, multi-theater complex, and a central plaza with three levels of high-end retail and restaurant space.
The resulting simulation database greatly benefited the development process of this project in a number of ways. Beyond using snapshots of the database for an environmental impact report, Ira Smedra used the simulation to study the physical impacts of the development plan from various angles to scale. This interactive process allowed him to "look" out windows and modify buildings where windows were unexpectedly blocked. The simulation also allowed the development team and the project architect (Kanner Architects) to discover problems in the design of the main plaza space.
"We saw that the original location of the escalators interrupted the flow of (a proposed) pedestrian plaza. We also saw that by moving the escalators to the far end, we were able to achieve a nice, open feeling," said Smedra.7
The USTís simulation of the project was also used as an interactive visualization tool to inform and empower the Westwood community of the projectís physical impacts. The local residents and merchants were invited to a community meeting by the local Councilman, Michael Feurer, to experience the proposed development of Westwood Village through the Urban Simulator interface. The participants were able to interactively fly, drive, or walk to any location in the Westwood neighborhood and view the project from that angle. As a result of this consensus-building meeting, the local community was able to give valuable input to the design and was also alleviated of certain fears related to the projectís scale.
Benefits to Stakeholders. Through this simulation technology, planners can realistically present and successfully develop "good" design decisions that help create consensus among the many stakeholders involved. Through the Teamís involvement in real-world projects such as Westwood Village, urban simulation has allowed the empowerment of stakeholders from the professional designer to the neighborhood layperson. More than the services of a well-trained designer or planner, a well-planned neighborhood requires good translators and good teachers. With the capabilities of urban simulation, planners and designers will be more effective in teaching laypeople the tools of design, translate a design solution to meet the felt needs of the community, and empower them to engage in participatory design for building true consensus.
The "Stakeholders" of any development and their benefits from using urban simulation technology include the following:
Because of its unique interface, the numerous benefits of urban simulation as a visualization tool are evident. Its illustrative and empowering capabilities allows it to be a revolutionary component to the planning process. Councilman Mike Hernandez of the Los Angeles Mayorís Office explained, "The real value is to allow citizens to participate in the planning process. It really benefits in developing large projects and in looking at the impacts of those projects on communities. With virtual reality, you can actually see it before you build it."8
Scarcely a week goes by without at least one new application being suggested for the Virtual Los Angeles database and the urban simulation system. As demonstrated by the Westwood Village project, the Teamís simulation system is extremely valuable at placing new development into the existing built environment so that it can be evaluated in its actual urban context. This system allows the Urban Simulation Team to include virtually everyone in the planning process, expert and layman alike. The Team has found that designers, architects, developers, and consultants are able to identify real problems (which they were completely unaware of) and remedy those problems long before the first hole on a new development is dug.9
Besides the visualization of urban developments, other planning applications explored by the Urban Simulation Team include the following:
The UCLA Urban Simulation Team has successfully implemented a system, which combines custom simulation software and real-time database technologies with efficient modeling methodologies. This urban simulation system is being used for a wide variety of "real world" planning projects including that of creating a virtual model of the entire Los Angeles Basin. The system has proven to be an extremely useful tool for identifying potential planning problems and quickly exploring a large number of alternative design solutions. The interactivity, intuitiveness, flexibility, photo-realism, and adaptability of urban simulation make this technology an extremely effective tool for interactive design and consensus building in the intricate process of city planning.