Although there have been some pretty big additive modeling projects done, consider this: 400 city blocks and 1,000 buildings of four-square miles of downtown Chicago. OK, not full-size, but in a 25- x 35-ft model that was created by the Columbian Model and Exhibit Works (columbianmodel.googlepages.com/cmew) as part of the city’s bid for the 2016 Olympic Summer Games. “We had to redraw just about every building to make it suitable for stereolithography,” says Cathy Tinker, project manager and owner of the firm.

To create the model that goes from Lake Michigan to Halsted on the west; and from Oak Street to 16th Street on the south. Tinker and her colleagues used renderings of historical and residential buildings that they’d previously developed and purchased 3D blueprints from CyberCity 3D (cybercity3d.com), a 3D geospatial modeling company, as well as other commercially available scans of the city. For good measure, Tinker validated the designs using Google Earth and Google modeling tool, SkectchUp. Baxter Healthcare (baxter.com) and DSM Somos (dsmsomos.com) contributed to the project, using their own in-house SLA machines. Somos also provided the SLA resins, including its WaterShed XC 11122, ProtoGen Gray 18920, and SOMOS 14122, to produce each of the buildings. In all, 3,000 working hours were required to build the city.

The exhibit, on display at the Chicago Architecture Foundation, includes an overhead lighting system that mimics the daily migration of the sun, turning dawn into twilight in 15 minutes. “One of the fun things about the model is the sight lines; you get an amazing understanding of how the buildings cast their shadows,” Tinker says. “That’s sometimes hard to visualize digitally, but it works well in the physical model.”