We asked Megan Berkheiser and Mike Caldwell (the artists behind the 2012 poster Smarter, Greener, Better) to explain how they made the model featured in our spring poster. Read on to learn about their intricate process. 1. This piece originated from simple, 2D pencil sketches. Can you talk a little bit about the process that took it from there to the complex 3D model that was photographed for the poster? One of the aspects my partner and I find beautiful about New York City is the vast…