Proposed designs for a new San Francisco Bay Bridge were recently brought to life with the help of real-time 3D graphics technologies developed by Silicon Graphics Inc. (Mountain View, CA) and Coryphaeus Software Inc. (Los Gatos, CA). Three new designs for the Bay Bridge, damaged in the 1989 Loma Prieta earthquake, were digitally simulated using a new 3D urban simulation application called MetroSim from Coryphaeus running on Silicon Graphics Onyx2 InfiniteReality systems.
The bridge simulations are letting municipal planners, civil engineers, and government officials actually "fly through" the three designs being considered for the proposed $1.3 billion reconstruction of the landmark bridge’s Eastern Span — which extends from Oakland to Yerba Buena Island. The immersive and realistic simulations are visually more powerful than pre-created animations, because viewers can go wherever they want and see the bridge and its surroundings from any angle. They can experience what it is like to drive on the bridge, to pilot a ship beneath the structure, or fly above it in an airplane.
After an independent study commissioned by the California Department of Transportation (Caltrans) recommended that the Bay Bridge’s Eastern Span be rebuilt instead of retrofitted, the state’s transportation agency has been accepting design proposals for a new, earthquake-safe Bay Bridge.
Of the several designs submitted, urban simulations were created from the three designs that directly resulted from the study — the Skyway, a simpler and lower-cost option; the Single Cable Stay, a mid-range rebuild alternative; and the Double Cable Stay, a more elaborate "landmark" design. The three simulations took a total of four man-weeks to complete. After a series of reviewXxGET http://siteinfo.a9.com/data/6lSv01 Bay Bridge seismic enhancement is scheduled to be completed by 2004.
To create the bridge simulations, engineers used MetroSim, a new real-time graphics application unveiled by Coryphaeus Software last month. With this software running on a Silicon Graphics Onyx2 workstation, engineers combined existing 3D wireframe models of each bridge design with a wide variety of real-world data. This real-world content included Bay Area terrain data supplied by the US Geological Survey; a 5-meter satellite image of the Bay Area and its surroundings from ImageLinks; bridge textures; high-resolution models of the nearby Golden Gate Bridge, Treasure Island buildings, and ships from Viewpoint DataLabs; and photorealistic skylines of both San Francisco and Oakland. The resulting simulations place viewers in an immersive and realistic environment to give them a true sense of the bridge’s appearance in its surrounding environment.
"Urban simulation vastly broadens the use of real-time 3D graphics technology beyond its traditional applications in defense, aerospace, and entertainment," said John Murphy, president of Coryphaeus Software. Drew Henry, director of advanced graphics marketing at Silicon Graphics added, "Since most of the cost of a major construction project is committed when a design concept is chosen, urban simulations can save project planners millions by giving them the best possible insight into the final result even before construction begins."
Coryphaeus Software’s MetroSim was developed specifically for modeling urban scenes that incorporate buildings, roads, rivers, trees, and vehicles. With these simulations, developers and planners can interactively visualize the many components, building types, and infrastructure that comprise cities, as well as entire cities. MetroSim integrates three Coryphaeus tools to provide a comprehensive urban simulation software solution — Designer’s Workbench for real-time 3D modeling, texturing, and model optimization; DXF Translator for importing existing graphics files; and EasyScene for establishing the environment and real-time display. Complementing MetroSim is EasyT, Coryphaeus’ tool for creating massive databases of data used for creating realistic simulations.
