The capital of Finland first tested city modeling as long back as 1987. But the most recent model of the Kalasatama district demonstrates the new state-of-the-art possibilities of this technology: creation of a highly accurate digital twin of the city.
My hosts, Helsinki’s city modeling specialists Jarmo Suomisto and Enni Airaksinen, showed me their latest projects. One of them offered a glimpse of history through a lens of the future.
With 3D glasses on, I was able to experience the unrealized city plan made by Eliel Saarinen, the father of the world-renowned architect Eero Saarinen. The virtual model in question was a digitized version of a huge physical model from 1915. Being able to stroll the streets and fly over the roofs of the imagined city really made me understand how awesome the original design was. I had seen a scale model of this same plan while it was laid in the foyer of the Museum of Finnish Architecture many years ago, but this experience was quite different.
The makers of the virtual Saarinen model, the Helsinki 3D+ team, used the same technique as they would use with a real-sized city. They took 3000 photos and programmatically turned them into a point cloud and further into a triangular mesh. In the case of digitizing the real Helsinki, an airplane took over 42,000 pictures at 1.2 kilometers height, all with astounding accuracy. The length of a pixel in those photos equated to 7.5 centimeters (3 inches) on the ground.