Metropolitan Scale Four-Dimensional Models

The GSD Metropolitan Model Collaborative

Three dimensional digital models are useful for many purposes. We may need to visualize the topography of urban areas in three dimensions to plan for a night on the town or to respond to an emergency. We may need a 3d visualization of a historic urban scene to investigate a situation that doesn't exist anymore. Or we may need a model of an urban place as a starting place to communicate our ideas for a future design scenario. We may want to share these models with the world through a viewer such as Google Earth; or use the model in GIS for analyses such as broad-scale view studies or complex, animated flythroughs of expansive areas. Or we may want a 3d model integrated with our institutional administrative data infrastructure. These applications are illustratied below, and accessible as tutorials with sample data in the navigation panel to the left of this page.

The most complete, authoritative, broad-ranging and versatile 3D model of a city will be compiled from the work of many sources. Many very valuable 3d models of specific areas already exist, created for project specific purposes. The Metropolian Model Collective provides a container and a method for consolodating these resources, either within a single firm or agency, or with the greater community. For an overview of this project, see slides from the 2008 ESRI User Conference The repository is based on a relational database schema discussed in this paper This entire project and all of its ins and outs are the subject of a GSD Course: GeoWeb: Virtual Worlds as Public Infrastructure And the subject of a symposium to be held at the GSD in the summer of 2003, 2006, and 2010.

Visualization, Curent and Future Views of the City

Having All of these models in a large, scaleable database schema allow us to use database logic to retrieve logically consistent views of the city based on past, present and future conditions. Any numer of different thematic views may be drawn upon -- including commercial or emergency management themes.

Sharng of Three Dimensional Documents

To let your clients or contituents (or your mom!) view your scenarios in Google Earth You can uese the model repository to share scenarios as a simple file that can be attached to an email, or posted on your web site, like this:

Note that you will need to have installed the free google earth viewer. If your browser is not trained to recognize KMZ files, this file may open in WinZip. If so, just double-click on the doc.kml file inside. The three gund hall scenarios will be sub-folders within the your Temporary Places folder on the Left-hand Places folder in google earth. Choose a room placemark from the 5th floor rooms placemarks file. Turn on the Fifth Floor floorplans. These will be clearer if you turn up the transparency of the current view buildings.

Knowledge Management

The Graduate School of Design is an engine of understanding. The school is a laboratory for techniques and workflows for collecting transforming and presenting information concerning alternative futures. For better or worse, much of the knowledge and information that is collected and generated over the course of a term is lost. One of the questions that we are asking inthe Virtual City Collective, is how can we take the products of independent scholars and aggregate them into a coherent model of the city?

THis diagram outlines the workflow for developnig a database for collecting representations of the city, collected wholesale by airborne laser scanners and photography, but also updated and elaborated by more detailed representations of existing and historic conditions, and also proposed schemes. To read more about how this infrastructure works, see A Data Model for a Temporally Diverse Metropolitan Model.

Video Presentations

Virtual City Models like ArcGIS, Sketchup and Google Earth provide a means of presnting choreagraphed presentations of complicated 3d situations via animations.

This animation, created with Google Earth presnts some ideas related to the placement of an ornamental tower in Boston's City Hall Plaza.

The next animation shows of some of the capabilities of Google Sketchup for creating stylaized renderings and shadow studies.

These animations were part of a project entitled A Shared Laboratory for Rethinkiing City Hall Plaza which was part of the cours: GeoWeb, Virtual Worlds as Public Infrastructure.

Public Participation

The web is characterized by very inexpensive or free tools for authoring and sharing information. When applied to geographical representaion, we see new and exciting prospects for sharing information about places. How should this change the expectations of the public to be able to have three dimensional models of proposed developments? It is very exciting to see how this technology is allowing citizens to develop their own proposals. The Virtual City Collective is an example of the exploitation of a completely free infrastucture for sharing resources useful for developing broad-scale 3d ideas that can be shared and explored with Google Earth.

The Google Earth Trainset is a demonstration of how the Virtual City Collective was extended to study the feasibility of extending the MBTA Greenline past East Cambridge as a streetcar i McGrath Highway.


Having many different formats in the model repository allow us to use the models for editing in Sketchup, or to uese them in GIS for analytical studies. This study uses the Viewshed function in ArcGIS to analyze threatened views of the Zakim Bridge. For a more elaborate presentation of broad-scale view corridor analysis, take a look at An Urban Design Laboratory for Belfast, Northern Ireland For best results, save this pdf file to your computer and open it with Acrobat viewer. It does not work well when viewed inside your web browser.

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Administrative Information Infrastructure

Understanding and managing the things that happen to be in Cities and buildings benefits from understanding their location in 3d space. Administrative database are full of spatial references that we can coordinate with three dimensional models to improve opur understanding of how to make things work. This example takes the CAD floorplans of the GSD and coordinates them with our model. These are exported to the google earth link, above.