Sgraffito in 3D [artistic concept]

“All pottery is a copy. The only question is what the copy is aiming for, what element of the original it is seeking to emulate”.

These are the words of Japanese cook and potter Kitaoji Rosanjin (1883-1959). In the pre-industrial era historical reproductions of functional ceramics were already being massproduced. Rosanjin pointed out a central facet in the design of pottery: historical objects have always been a model and reference point for contemporary ceramics – and will continue to be so.

Today copying has become easier than ever through the digitization of information. In the near future personal 3D-printers, with which we shall make prints of 3D objects that we have downloaded from the Internet, will become affordable. We will decorate our homes with 3D-prints or use them to replace broken parts. Virtual Reality goggles (head-mounted displays) are going to become both lightweight and wide-screen. Image processing technology is becoming faster and cheaper. Designers, artists and marketers will enrich our physical reality with an extra audio-visual information layer. This mix of tactile/physical reality and real time simulation will be part of our daily lives.

Human interaction with physical reality is already being influenced by the massive use of computers. Technology – embedded in everyday objects – is a language of culture. It has a narrative potential. Deriving from the Greek word ‘techné’, it not only stands for the activities and skills of craftsmen, but also for the arts of the mind (science) and fine arts. The cut-copy-paste computer-allegory for human perception, thinking and acting forms the foundation of the exhibition ‘Sgraffito in 3D’. The process of scanning, archiving and printing in 3D is illustrated in a collection of installations. The visitor can walk through the process and interact with the products of each of its components. The pre-industrial cultural heritage is re-interpreted with post-industrial technology and made digitally accessible online.

In ‘Sgraffito in 3D’ art, technology and science merge into one total art-installation (gesamtkunstwerk). To discover the influence of (re)production techniques on the socio-political state of the artwork, pragmatic research has been applied on these separate domains – the academic world, the art world, and the industrial world – which overlap within the artistic intervention.

Collection

Sgraffito is the name for ceramics in which patterns are scratched into a top layer of white slip when the clay is wet. This centuries-old decorative technique was introduced into Western Europe by way of Persia and the Byzantine Empire. In the 15th and 16th centuries Dutch potters also used these ‘drawings in clay’ on simple, everyday earthenware.

The sgraffito collection of Museum Boijmans Van Beuningen dates from the period 1450-1550. The Dutch plates, bowls and cooking pots are part of the Van Beuningen-De Vriese collection. Art historical research of the collection of Museum Boijmans Van Beuningen was done by curator Historic Design Drs. Alexandra Gaba-Van Dongen, Dr. Joanita Vroom and art history students Femke Speelberg and Jacoline Zilverschoon. Their writings are published in the research section.

The futuristic aura of the museum’s brutalist-style concrete architecture, the large glass windows and the rusted metal Richard Serra artwork formed the base of the overall design of the exhibition. The collection was placed in a semi-circle in space so that it could communicate with the metal artwork through which visitors entered. The collection was exhibited on glass vitrine-shelves and was approachable from all sides so that maximum transparency was realized. The collection was digitally photographed and made available online in the collection section of this site.

Technical and spatial specifications:
The collection comprises approximately 100 sgraffito objects ranging from 5 to 50 centimeters in size. The vitrines used in the exhibition are property of Museum Boijmans Van Beuningen.

Computed Tomography [CT-Scan]

Twenty-two objects from the sgraffito earthenware collection were scanned with a CT-scanner belonging to the Erasmus Medical Centre in Rotterdam. The CT-Scan video is an artistic interpretation of this process, created with the aid of medical visualization software. The original lines along which the sgraffito objects were broken and restored are clearly visible in the CT-Scan.

Computed Tomography (CT) uses X-rays. The absorption of photons by the earthenware pot is measured on all sides. Different materials (i.e. plaster, glaze, ceramics) have different absorption values. These measurements are converted into hundreds of digital ‘slices’ approximately half a millimeter thick, from which the computer makes a three-dimensional image in voxels. The different materials become visible as gray values. CT-scanning techniques are usually used for screening the human body, but this technology can also be important in art-historical and archaeological research. The virtual reconstruction is so exact that an object can be meticulously studied, for example for design (typology), decoration technique and signs of use or damage.

Technical and spatial specifications:
1 video projector (min. lumen 5500) + DVD player. Wall or projection-screen size: min. 3m x 4m.

Protagonist - Antagonist

Seven protagonists of the collection were copied through the process of 3D-scanning and 3D-printing. These clones, the antagonists, were placed in front of the archaeological objects. In a break with tradition, visitors could take these objects in their hands and with their fingers follow the traces drawn half a millennium ago while looking through the glass of the vitrine at the real untouchable object. The 3D-printed clones thus mediate the archaeological objects through tactile feedback. All 14 objects stand on pedestals with built-in pulsating lights, which light up the objects from underneath. When lights shine through the nylon replicas the iconography of the sgraffito carvings becomes visible.

The scans from the CT-Scan – the previous step in the process – were converted into high-density 3D-pointclouds using medical visualization software. Through a process of polygon reduction and (manual) reverse engineering the high-res 3Dobjects are made suitable for 3D-printing. The antagonists were printed with a Selective Laser Sintering (SLS) 3D-printer at the Rapid Manufacturing Demo Center of TNO Science and Industry in Eindhoven. These SLS prints are durable and strong and can even be put in the dishwasher!

Technical and spatial specifications:
14 Light pedestals incl. bottom light, 7 glass vitrines diameter min. 90 centimeters, 2 separate electricity groups, XLR cables, DMX programmable pocket recorder, electricity cables, 14 pin spots.
Whole installation: approx. 8m x 2m x 2.5m
Light pedestal with clone: 0.5m x 0.5m x 0.9m
Vitrine with light pedestal and original: 0.9m x 0.9m x 2.5m

3D Archive [+ website]

The installation is the result of research into what a virtual 3D archive of digitalized cultural heritage could look like.

The design of the 3D Archive is based on the kind of pits in which many archaeological discoveries are made. Visitors of the archive can lean on the balustrade and socialize while looking into the depths of the well from which sgraffito objects can be summoned. Each of the seven protagonists has its own button on the archive’s interface and can be seen from all sides by using a backlit trackball. There are buttons on the interface to break the object up in shards (deconstruction) and make it whole again (reconstruction). The last button brings up iconographic references in the image, in other words paintings and prints from the museum collection that relate to the object. A basic version of this interactive archive is available on the project website.

The website is in fact an extension of the 3D archive installation. All sgraffito objects were digitally photographed (front, top and perspective view), their iconography was categorized and places of production and excavation sites were added. Thus the collection was made available for researchers and enthusiasts all over the world. Additionally the 3D objects can be downloaded for private use. A researcher might print the archaeological object in 3D to put on his desk and keep as a reference; another person might print it in 3D to decorate his home.

In order to be able to manipulate the virtual pottery in a 3Dengine the high-resolution models resulting from the Protagonist/ Antagonist installation were converted into low-polygon models. The low-polygon models were then cut along the lines where they had once been broken. The interaction of the electronic hardware with Unity3D was programmed in Wiring. The interaction of the virtual pottery with the electronic interface was programmed in Unity3D. A simplified version of this Unity3D program was exported to the web.

Technical and spatial specifications:
3D Archive: 1 computer with a graphical card suitable for gaming, 1 video projector (min. lumen 6500) suitable for direct floor projection (option: video projector + surface mirror).
3D-Archive diameter:±3m
3D-Archive height: 0.9m

Website:
Computer with the opera web browser installed (to allow kiosk mode), LCD screen, Ethernet connection

Augmented Reality [AR]

Augmented Reality is a technology that enables you to see virtual objects visually mapped onto the real world. In the Reconstruction Lab and the 3D Pop-Up Book installations a web cam determines the position of the virtual objects in reality by visual marker recognition (comparable to 2D-barcode scanning). For these installations Joachim Rotteveel collaborated with the AR+RFID Lab of the Royal Academy of Art in The Hague.

Desktop-AR was chosen for both installations because the stability of such a system makes it suitable for a low-maintenance museum context. However, during the opening of ‘Sgraffito in 3D’ a performance was done using mobile ARbackpacks, developed at the TU-Delft, in which visitors could deck a table with virtual pottery.

3D Pop-Up Book

The 3D Pop-Up Book is an elegantly printed, large format book of poetry complementing the iconography of the sgraffito protagonists with writings and music of its time. When held before a web cam the book becomes the interface for medieval soundscapes and animations of the 2D carvings moving out of, then back into, its dish in 3D. Curator Historic Design Drs. Alexandra Gaba-Van Dongen and medieval music expert Margot Kalse chose the texts and music on the basis of their research into the iconography.

The iconography was isolated from the original digital photography of the sgraffito objects in Adobe Illustrator. The iconography was then Photoshopped out of the texture, which was mapped onto the low-polygon virtual model. The iconography and retouched model were imported into the 3D software and animated. The virtual animated dishes were eventually mapped onto the optical markers in the book for display in Augmented Reality software.

Technical and spatial specifications:
PC, 1 computer with a graphical card suitable for gaming, an LCD screen (90cm width) of adjustable height, a high resolution web cam to place on top of the LCD screen, a pair of headphones
Size approx. 1m x 0.75 x 0.5

Reconstruction Lab

What if archaeological objects could tell you about their history? Imagine holding a 3D-printed shard of pottery in front of a web cam, which then reveals to you how it was once whole, that it got broken and then later was reconstructed.

In Reconstruction Lab the archaeological pottery tells visitors about its history. By holding a 3D-printed shard of pottery in front of a web cam it reveals to you its missing pieces. The 3D-printed shard acts as an interface for the virtual object: when you move the shard in your hand you move both the physical and virtual object simultaneously as if it were one object.

In the CT-scan the different materials composing the objects were highlighted and broken pieces were revealed. Along these lines the 3D-objects were cut. From each sgraffito object a shard was chosen and merged in 3D with a pedestal with a visual marker imprint. These shards were printed with a Selective Laser Sintering (SLS) 3D-printer. The virtual shards were then mapped onto the 3D-printed shard for display using Augmented Reality software.

Technical and spatial specifications:
PC, 1 computer with a graphical card suitable for gaming, an LCD screen (90cm width) of adjustable height, a high resolution web cam to place on top of the LCD screen
Size approx. 1m x 0.75 x 0.5

Sketches for Exhibiting

The following picture shows an example of ways ‘Sgraffito in 3D’ could be displayed. The installations are modular and independent of a specific placing. Curators of a festival could adapt the placing according to the space. All installations have been designed to be easily taken apart for transport.

The first shows a setup in which all installations are included:
• Protagonist/Antagonist
• The CT-Scan video
• The 3D-Archive
• A round table with on one side the 3D Pop-up Book and on
the other side the Reconstruction Lab
The second render shows the basic setup against a wall with the following installations:
• Half of the Protagonist/Antagonist-installation:
[ 7 Antagonists with their light-pedestals ]
• The CT-Scan video
• Reconstruction Lab