Ma­chi­ne Trans­la­ti­ons

Although «Incidental Space» was designed on a physical model, the project radically demonstrates the possibilities of digital technologies in architecture. A principal characteristic of architectural design compared to other arts is that the final product is indirectly controlled with models and drawings (Robin Evans)¹. The challenge of «Incidental Space» was to design the process of the necessary translations from model to space, in such a way that any non-intentional influences on the form were reduced. The goal was to approximate the ideal of a lossless reproduction in order to achieve a spatial high fidelity.

Oscillations of Form

The form of the installation is irrational: it defies any description with known geometrical vocabulary, formula or conventional architectural orders. For the materialization, new methods of digital fabrication of high-resolution freeform geometries had to be developed.

3D-printing played an important role in the process. For The usage of 3D-printed parts as building material, the quality of the materials and their structural capacities, still pose as a challenge for future research.² In the Biennale project, 3D-printing was used to fabricate complex freeform molds. Therefore, the construction could benefit from the unique properties of 3D printing, and combine the ornamental richness of intricate details with an efficient structural system which was built from an extremely fine thin shell fiber-reinforced concrete with a depth of 1 to 4cm.

For the realization, a process-chain was developed which consisted of a cascade series of digital and analogue translations starting from the first model to the fabrication of the final form. Thus the state of the original form oscillated between the positive and the negative: the original model as the positive, the plaster casting as the inverted volume, the scan as the point cloud, the mesh-geometry as the surface, the print-file as the volume, the CNC Mill as the path, the 3D print as the mold and finally as the sprayed concrete. The ideal surface was approximated through the interplay of several thin layers of material: the mold, the filler, the separator and the thin shell concrete skin.

Resolution: The Surface of a Cloud

The plaster cast of the assemblage abstracts the model into pure form, removing any information about the materiality. With the combination of two industrial 3D-scanning strategies, the model could be digitalized to a discrete set of 3D data-points. While the surface-structure was scanned optically, the overall volume was scanned with computer tomography and translated with x-rays layer by layer to a digital model.

The surface of the point-cloud was translated by customized software to a closed triangular mesh. In order to preserve the details of the original model an an extremely high resolution was necessary. The following comparison illustrates the amount of information necessary: This text consists of approximately 6,000 symbols, whereas a highly detailed building model rarely requires more than 10,000,000 symbols. However, in order to describe the spatial information of the «Incidental Space» 60,000,000,000 symbols are needed.

Every attempt to compress the information of the «Incidental Space» is doomed to fail. The Gestalt has no repetitive parts, or regular surfaces that could be generalized by a formula.³ Every single face is unique and relevant for micro and macrostructure. Such geometry turns into a geography⁴ with a landscape which can be categorized in characteristic regions, just as the topography of a mountainous terrain.

Synthesis: Printing Form

While parts of the molds could be fabricated with CNC-milled foam, several regions were impossible to produce with a subtractive fabrication process. Therefore, for the first time in architecture, a freeform formwork sand-based 3D print was used in this large-scale 3D-print process. This system originates from mold making for the foundry industry.

Thin horizontal layers of the desired form are printed with a binder on fine sand. At the end of the printing process, a solidified geometry is embedded into a volume of loose sand, from which it can be retrieved similarly to an archeological excavation. Powder-based sand-printing allows for the fabrication of building parts with nearly no geometric constraints in a high precision, and the manufacturing of 3-dimensional construction details with undercuts, hollow structures and microstructure in a single fabrication process.

In the interplay with the software, the 3D-print mediates between the geometry of the material concrete. In the Swiss pavilion, the 3D print is an antipode to the 3D scan: the materialization of digital information without friction in highest density, manifested as form giving formwork for the structural skin of fiber-reinforced concrete.

The data-cloud is printed as a direct imprint of the surface. On the backside this skin is informed with constructive details. For the Biennale, a parametric software was developed which automatically generates the construction data for the formwork system. This includes the segmentation of the region in printable components, the reduction of material and weight through rip-structures, the connection details and the labeling of the parts. In order to use the printed space efficiently, the building parts are 3D nested automatically. This process allows the fabrication of hundreds of individual free-form molds.

Digital Powder and Digital Binder

The installation demonstrates how closely tied research, experiment and design are in architecture. It shows the potential of hybrid approaches. The complexity of the form was not controlled by a single system, but through an opportunistic symbiosis of coordinated fabrication strategies. An essential topic of interest is the application of 3D printing in architecture. 3D printing is the most radical form of digital fabrication and it has the ability to change in paradigm within its fabrication: customization and complexity are possible at no extra cost.

Digital technologies should not limit a design or push it in a specific direction, but insteadopen up new possibilities for design. They are successful, even if they leave almost no traces.