Call it instant gratification, but before I delved into the CityEngine tutorials, I wanted to experiment with modeling a supertall “hero” building. The most simple form I could think of was the Sears/Willis Tower, which is comprised of nine “bundled tubes”. As seen in Figure 1 and summarized in a Princeton University article, the structural plan consists “of 9 squares, each 75 feet across, placed in a three-by-three grid arrangement”. Tubes are extruded from these squares and terminated at various heights. This turned out to be excellent problem on which to improvise.
In the first version, I divided the building into five sections, the four floor plates plus the antenna farm on the roof, but I had to write and apply a separate rule for each section (Figure 2). I took two weeks of hard study before I could finally produce the entire, completed shape from a single start rule. (Figure 3) With this done, I was free to sprinkle Sears Tower shapes all over the landscape.
Figure 2: Floor plates set at proper elevations (left) and then extruded in the “bundled tube” design. (click to see a larger image)