Methodology

1. Research into the V&A Cast Courts collection and nineteenth-century copying and reproduction techniques; research into contemporary digital copying and reproduction techniques

This project began by thoroughly researching contemporary methodologies for recording and site-surveying, such as triangulation, photography and digital photogrammetry. Similar research was undertaken into modes of artefact production from mould-making and plaster casting methods of artefact production, both historical and contemporary. Technologies suitable for Infractus were ultimately chosen in conversation with the exhibition curators of A World of Fragile Parts and ScanLAB Projects who have unparalleled expertise in scanning material artefacts and buildings and reproducing them on web platforms and in immersive installations and objects.

19 Casting marks resulting from the use of multiple moulds are visible in many artefacts in the V&A Cast Courts, such as this bust of Piero di Cosimo de’Medici 1453 (sculpted) 1899 (cast).

2. Site recording by LiDAR and photographic techniques

Selected fragments of Robin Hood Gardens were captured using terrestrial, long-medium range, 3D-laser pulse-based scanning, using the FARO Focus3D X330, which scans 360 degrees at a distance of 0.6 to 330 m. The choice of scanner was determined by the dimensions of the site and spaces, as well as by access time to the site.

LiDAR scanning is by now a familiar tool for surveying built cultural heritage and is used widely in the field of archaeology and preservation to provide documentary records of vulnerable and inaccessible sites. It is a critical tool in non-contact documentation of cultural heritage, allowing for high-resolution 3D recordings of landscapes, monuments and artefacts (Factum Arte 2013).

Laser scanning produces millions of accurately measured points in the X, Y and Z axis, representing the surface of the scanned object. This point cloud of raw data can be converted to CAD and other imaging programs to produce accurate high-definition 3D models with very large data sets. Scanning a space is a relatively simple process that involves placing a terrestrial laser scanner on a tripod. As it rotates, an infra-red laser is bounced off a fast-spinning mirror. The device then records the precise position and distance of each point the laser hits.

Each scan contains millions of individually measured points, captured by the scanner as part of a 360-degree sphere of survey information. The resulting high-resolution point-cloud of data is a highly detailed 3D digital model; however, not all surfaces are captured perfectly. The rough-finished concrete of the Smithson’s design reflects the laser perfectly, but broken glass blocks and the gloss surface of lift shafts give slightly

mistaken measurements and noisy data. These mismeasurements, normally excluded by rigorous surveying filters, remain embedded. Like maker’s marks, they are telltale signs of a technology that on the one hand captures a meticulous and viable facsimile of the world, while on the other expresses the inherent imperfections of digital precision.

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20–1 Terrestrial LiDAR scanning used in an archaeological setting at Fort Conger, Ellesmere Island, Canadian Arctic Archipelago. This is a key heritage site of pioneering expeditions in the late 1870s and 80s, which is now threatened by climate change and human activity.

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22 Scanning interior and exterior spaces.

23 Stainless steel lift doors.

24 A security grill and abandoned soft toy.

25 A panel of broken glass bricks.

26 Remnants of a kitchen with exposed plumbing and electrics.

27 A net curtain folded into secondary glazing.

28 A triangular window looking out onto the ‘streets in the sky’.

3. 3D printing and the use of crystal etching

Glass engraving in 330 x 100 x 100 mm blocks was chosen as a method to capture and present the digital data collected from Robin Hood Gardens. Sub-surface laser engraving is used commercially to produce 3D images from 3D point clouds. Two lasers firing thousands of impulses are aimed into the cast glass block. 40 to 80 m fractures are produced where they rectify and create excess heat, each visible as a tiny dot floating in space. Glass with high optical clarity reduces the refractive index, which is important in ensuring the integrity of the image. The printing technology limits the number of points that can be used, as excessive fractures can weaken the glass blocks making them too fragile to exhibit. Indeed, the process required considerable experimentation as many of our test pieces failed, fracturing in the process of their making, and reminding us again of the fragility of the chosen medium.

29–34 (overleaf) Processing the point-cloud data into six sets of four blocks.

35 Infractus at A World of Fragile Parts, La Biennale di Venezia, 15th International Architecture Exhibition, 2016. Torches were supplied to light up the point cloud captured in the glass blocks.

36 Detail of laser-etched point cloud.