Stakeholder & Developer: Skidmore, Owings & Merrill, San Francisco
Process of SOM ‘s Digital Model
With over 20 ongoing projects in the Bay Area, SOM San Francisco decided to create a 3D Model of the city to better understand and analyze the complex environment of the City.
The creation of SOM’s digital model began with an analysis of historical and present-day maps. The underlying structure was City of San Francisco’s Geographic Information Systems (GIS) database, for this reason, 3D model would correspond directly to the 2D GIS data to simplify overlays of new geospatial data and future changes.
Because the GIS data is 2D and not intended for 3D visualization, the team then redefined the geometry of the streets and blocks to facilitate 3D operations. SOM created a curvilinear contour model of San Francisco and draped the 2D street grid over it, resulting in a 3D representation of the streetscape. The intersections were subsequently leveled automatically.
With this 3D groundwork in place, SOM then focused on the buildings. Because no database existed with comprehensive information on the City’s buildings, the team referred to aerial photographs, leasing plans, and design drawings to draw 2D outlines of building masses on appropriate parcels. Those outlines were projected onto the sloping ground planes and extruded vertically to create 3D buildings. Some of the buildings are simple box-like forms, while others are modeled in great detail.
The metadata is periodically checked for accuracy by two individuals in SOM’s Digital Design Group and linked to outside resources such as the city assessor’s office.
Model Use / Model User
The model records lot numbers, zoning restrictions, and other variables that SOM can use to create specific views to analyze issues like environmental conditions and their effect on existing and potential infrastructure. Moreover, the model is being used by the city planning department of SF to visualize potential zoning changes and development proposals.
City’s current height limits
Certainly, the digital model of SF is a good example how create and how use a urban information modeling.
By Soledad Hernandez