3D printing from topographic landscape model data

Vector data from the topographic landscape model are also suitable for producing models using a 3D printer. Together with an associate partner, swisstopo modelled the old town of Aarau in summer 2013 using this method.

Right: 3D image of the old town centre of Aarau. Left: the utilised building data from the topographic landscape model.
Right: 3D image of the old town centre of Aarau. Left: the utilised building data from the topographic landscape model.

The model of the old town of Aarau depicts the buildings from swissBUILDINGS3D 2.0 and the terrain from swissALTI3D at a scale of 1:2000. With the 3D printer, swisstopo produced a white print (monotone) and a colour print (roofs, walls and terrain in different colours). Below you will find additional information about the 3D printing process that was used.

Production

The print of the mock-up of the historic city center of Aarau has a dimension of 25 cm x 20.3 cm. It was manufactured directly out of the provided vector data with a high performance professional 3D powder printer. Roof overhangs were eliminated due to technical constraints.

Data base

The vector data was provided in the drawing exchange format “DXF”. 

  • Terrain: swissALTI3D formatted as TIN (Triangulated Irregular Network) 
  • Buildings: swissBUILDINGS3D 2.0* 


* Build-up in progress; currently incomplete nation-wide availability.

Printing Process

To perform a 3D print, the machine solidifies the provided powder material (e.g. plastic, sand, ceramic or glass powder) selectively with adhesive agent or glue. When printing, the powder tray is lowered step by step so that the successive printed layers are joined to form the final object. Finally the object is air-cleaned from redundant loose powder.

FAQ

No. For 3D printing, please contact a specialized 3D printing provider.

Typically, an STL file (STereoLithography or Standard Tesselation Language), extension .stl, is required. The extension .stl is used for stereolithographic CAD data. STL is one of the standard formats of many CAD systems and is used mainly for rapid prototyping and computer-aided manufacturing (CAM).

Most CAD software programs are able to export to STL. For example, import a DXF file into CAD software and then export it as SLT.

The data type provides information about the compression of the data. For this purpose, the more compact binary STL-format is quite sufficient.

For printing, the model must not contain any gaps. The model must be “watertight” and have a closed, continuous surface. The software of the 3D printer must be able to reliably recognize where the material should be built and where not.

With almost all 3D printers, details under 1mm are poorly reproduced, often out of focus or not even visible. Please note that the 3D model needs a continuous minimum wall thickness of 0.7mm. The degree of detail (“resolution” of a 3D printer) is a function of the printing technique and the material used.

In 3D printing, the model is built in additive layers. There are different concepts:

  • In Stereolithography (abbreviated to STL or SLA), layers of a polymer are cured by using light (a laser) in a vat of the liquid polymer.
  • In Selective Laser Sintering (SLS), a laser fuses together a material powder in layers.
  • In melt layering (Fused Deposition Modeling, FDM* or Fused Filament Fabrication, FFF) a heated material is applied drop by drop, similar to an inkjet printer.

     * Note: The term “Fused Deposition Modeling” and its acronym FDM are registered trademarks of the company Stratasys. An alternative term for this process is Fused Filament Fabrication (FFF)


Federal Office of Topography swisstopo Seftigenstrasse 264
P.O. Box
3084 Wabern
Tel.
+41 58 469 01 11

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Relevant authority

Topography
Geodata Distribution
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Print contact

Federal Office of Topography swisstopo

Seftigenstrasse 264
P.O. Box
3084 Wabern

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