City Modelling in 3D Print

Today’s guest blog comes from George Lee of Callprint in the UK.

There exists, rumoured to be filling many storage shelves of a warehouse in Zagreb, a 3D printed model of that city. Why is the model in storage? Because it measures 29 meters by 18 meters, and is made up of 3,000 tiles covering 29 x 18km of the city. No permanent home has yet been found to house it, which is not surprising given its prodigious size.

In the UK, Zmapping have modelled most of the city centres in the UK, and the data are used extensively under license by architects to 3D print context models in which to present their schemes. The data are constructed from Lidar scans, photogrammetry and manual modelling in CAD. Some buildings on the model have reputedly been measured to be within 15cm of the real world buildings that they represent.

Tower of London model from Zmapping data, 3D printed on ZPrinter 650, Courtesy of Buchanan Architects

In recent years there has been a proliferation of companies creating and selling city models for a variety of purposes. For many, 3D printing is an afterthought. This is perhaps partly a reflection on lack of awareness of 3D printing and also a propensity for software developers to think solely in terms of the virtual space.

This is paralleled with the lack of real interest shown in 3D printing by the major BIM software vendors. But many exciting things are happening within the virtual database linked spaces of BIM and the city modelling developers. The Zagreb model created by Geofoto is a data base containing data derived from Lidar, with some manual input, where the roofs of each building are defined. For the purposes of 3D printing, the roofs are simply extruded into the topography and a 3D printed model is generated.

There are many clever people out there creating ever more ingenious virtual spaces. However to communicate a model of a city there is nothing that beats a physical model. 3D printing is the natural link between the computer model and the physical model.

The 1:1500 Pipers model of central London created by layering up 2mm slabs of acrylic cut on a laser cutter still draws crowds of locals and tourists alike. Imagine a model of your city 3D printed in colour on a ZPrinter 650. The benefits to the city of a physical model are manifold, for planning, education, tourism and even dare I say it for social cohesion. To stand together before your city and physically see how parts make up the whole is something that just cannot be done on a computer screen.