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 1:2,000. 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 centre of Aarau measures 25 x 20.3centimetres. 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 bases

The vector data were provided in the drawing exchange format  «DXF».  

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

Printing process

To produce a 3D printout, the machine solidifies the provided powder material (e.g. plastic, sand, ceramic or glass powder) selectively with an 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 to remove loose powder.

FAQs

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

Typically, an STL file (STereoLithography or Standard Tesselation Language), extension .stl, is required. This extension 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 programs are able to export to STL. For example, import a DXF file into CAD software and then export it as STL.

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. It must be watertight and have a closed, continuous surface. The software of the 3D printer must be able to reliably recognise where the material should be built and where not.

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

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 Modelling, FDM* or Fused Filament Fabrication, FFF) a heated material is applied drop by drop, similar to the method used in 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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