New life in Old Digital Models

The 3D computer-generated models and animations of the Old Minster of Winchester were remarkable in 1984-6 for producing the earliest animated tour of a virtual archaeological monument. Thought to be lost, thirty years on the original model files were rediscovered buried under layers of now unsupported code and recovered. The models written in a proprietary CSG modeller called Winsom turned up again last spring (2015). The full story of their rediscovery, restitution and recent transmogrification,  written with Stephen Todd and Andrew Walter, will be found – with models and animations- in (Reilly, Todd and Walter 2016).

In short the original models were transcoded from Winsom into an opensource solid modeller (i.e. OpenSCAD), and in modernising the digital Old Minster the original virtual model of the final phase of the Anglo-Saxon Priory Cathedral reimagined prior to its demolition in 1094 has also been translated into a material one in the form of a 3D-print.

Exhibit: WebGL rendering of half section of final phase of ‘Old Minster, Winchester’ re-imagined prior to being demolished in CE 1093/4 (http://programbits.co.uk/minster/minst.html)

Digital assemblages and objects like their physical counterparts gather histories around themselves as they accumulate new significance, connections and meaning throughout their existence (see, for example, Reilly 2015c). The biography of the digital ‘Old Minster, Winchester’ is a case in point. The rediscovery in April 2015 of model definition files, previously thought lost, led to the recovery of the original solid models’ exact geometry. This, in turn, enabled them to be transcoded and then re-presented graphically.  Advances in additive manufacturing technology now enable new kinds of intra-actions with these models, and allows nascent objects, such as cut-away models, inherent in the model files to be instantiated as physical outputs in a variety of different materials and scales (i.e. 3D printed Virtual Heritage ) for further multimodal exploration.

Currently, this apparent potential to align virtual and physical heritage appears to be under-theorised and, if left unaddressed, is set to radically disrupt current best practice in the discipline (see for example Reilly 2015a). Increasingly affordable additive manufacturing represents both an opportunity and a challenge to virtual heritage (Reilly 2015b). On the one hand, 3D printed heritage exhibits the attractive qualities of tangibility and durability, and is amenable to the well-rehearsed processes for curating physical objects. On the other, material instantiations of ‘virtual’ heritage may reintroduce intellectual opaqueness into the models once they are decoupled from the metadata and paradata that previously accorded them the status of being scientifically transparent (see Bentkowska-Kafel, Denard and Baker 2012).  What is at issue here is that like all 3D printable objects, heritage assemblages can be reiterated and, crucially, re-contextualised by anyone, anywhere in the world with access to the web.

In such circumstances, how can virtual heritage practitioners adhere to the London Charter’s central principle of accurately conveying to users the status of the knowledge that these new objects represent, such as distinctions between evidence and hypothesis, and between different levels of probability? There is a manifest need for an implementation of the London Charter guidelines focused on ‘virtual-material heritage’ outputs. Clearly, this warrants extensive and critical discussion within the expert community to establish new de facto standards to which such virtual-material outputs should be held accountable.

In the course of this rediscovery project we learned first-hand that 3D computer-based archaeological and cultural heritage models, built with emerging technology, have a very limited shelf-life unless exceptional measures are put in place to sustain them. Consequently, identifying and curating the many landmark virtual objects which have been developed on a huge array of technology bases over the last 30 years will be a weighty challenge for historians and curators wishing to take stock of the inception, early years and key developments in virtual heritage.

Finally, returning to the Old Minster, this virtual heritage model is once again a ‘needy digital object’ calling for an appropriate access and sustainability strategy to be developed (Edmond 2015). The project has returned to the status of a ‘work in progress’.  Moving forward, a number of areas within the model that were originally incomplete (because the virtual tour never visited them) can be developed to agree with the evidence available from the original archaeological, historical and comparative research. In addition to extending the biographical threads pertaining to the Old Minster models, the entangled biographical threads of the modelling technology used to instantiate these geometrically-defined hypotheses are also being drawn out. For example, the Old Minster models are implicated in the development of another reincarnation of Winsom called GOW (Grandson of Winsom) which, hopefully, will soon be released as open source.

References

Bentkowska-Kafel, A., Baker, D. and Denard, H. (eds) 2012. Paradata and Transparency in Virtual Heritage, Digital Research in the Arts and Humanities Series. Farnham: Ashgate.

Edmond, J. 2015. Collaboration and Infrastructure, in: Schreibman, S., Siemens, R. and Unsworth, J. (eds), A New Companion to Digital Humanities. Chichester: John Wiley & Sons, Ltd. DOI: 10.1002/9781118680605.ch4.

Reilly, P. 2015a. Putting the Materials Back into Virtual Archaeology, in: Hookk, D. (Ed.), Virtual Archaeology (Methods and Benefits). St. Petersburg: The State Hermitage Publishers, 2015, 12-21. http://www.academia.edu/15076178/Putting_the_Materials_Back_into_Virtual_Archaeology

Reilly, P. 2015b. Additive Archaeology: An Alternative Framework for Recontextualising Archaeological Entities, Open Archaeology, 1 (1), ISSN (Online) 2300-6560, DOI: 10.1515/opar-2015-0013, October 2015.

Reilly, P. 2015c. Palimpsests of Immaterial Assemblages Taken out of Context: Tracing Pompeians from the Void into the Digital, Norwegian Archaeological Review, DOI: 10.1080/00293652.2015.1086812

Reilly, P., Todd, S. and Walter, A. 2016. Rediscovering and Modernising the Old Minster of Winchester, Digital Applications in Archaeology and Cultural Heritage, 2016. DOI: 10.1016/j.daach.2016.04.001

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Husks, Seeds and winter is coming

It’s autumn here and the farmers are still working hard in the countryside to gather in the last of their crops and prepare their fields for the future. The grain harvest looks to be bountiful; winnowed husks given to the winds; the precious seeds meticulously separated, stored and preserved.

Husks and seeds have captured my imagination at the moment. I’m working on a paper which explores some potentialities of additive manufacturing (AM) technologies, e.g., 3D printing, to better inform us about archaeological remains – physical deposits, structures and objects – and the methods archaeologists deploy to ‘record’, ‘restore’ or ‘preserve’ them.

Researchers around the world are doing extraordinary creative things with AM technology. Museum curators, for example, at the Smithsonian in USA , are able to scan exquisite, rare and exciting, materially vibrant objects from around the world and make them available to be rematerialised anywhere else on the planet possessing an internet connection, a web device, and a re-fabrication unit. This is without a doubt a novel, profoundly important, multi-valent arena in the cultural heritage industry in which many new voices can be added to the narrative.

But what are these objects that are being created? They aren’t exactly copies because they can be scaled up or down, reiterated in different materials, at uneven resolutions, features enhanced, and so on. Yes, they resemble the prototype they are based on, but they are not the same. In some ways they are like our autumn husks, empty, devoid of content, or filled with an undifferentiated, but expensive and sterile polymer-impregnated space. On the surface they may be aesthetically pleasing, indeed very cool or sexy. However, more prosaically, like the original object they were based on, they are still subject to decay, mishandling and abuse, and so, ironically, as Victor Buchli (2010) shows, it is the “immaterial code” that the printers use to reprint the object of interest that emerges as the most stable entity in this extended assemblage. Both the old originals and the new originals are mortal. They are potent, but not as virile as those digitally recorded prototypical encoded seeds, immutable, transcendent, and promiscuous, and instantly transportable to any transcultural domain to be reproduced, abused or, possibly, recontextualised.

Ontologically fecund, but winter is coming

Disciplinary Grand Challenge: Additive Archaeology

In a previous blog, I outlined how virtual archaeology was originally conceived as an approach by which technology could be harnessed, in order to achieve new ways of documenting interpreting, annotating and narrating primary archaeological materials and processes, by inviting practitioners to explore the interplay between digital and conventional archaeological practice. As such, it wasn’t just about ‘what was’ or even ‘what persists’, it was also a generative concept allowing for creativity and improvisation including ‘what might come to be’. Here, I want to share some more ideas which have crystallised out through discussions with my friend and colleague Gareth Beale, at the University of York, UK. (N.B. More in press)  To begin, let’s as it were remove our gaze off the broad landscape of virtual archaeology and concentrate our senses on one exciting and potentially  disruptive virtual archaeology technology which seems to us to offer greater cognitive depth: additive manufacturing (AM). 3D printing, or rapid prototyping, is one form of AM experiencing a great deal of hype at the moment. However, AM more generally, encompasses a set of far more mature and for archaeologists, more profoundly relevant technologies. At a very high level, the huge array of available AM technologies can be loosely classified into three families (for a full treatment refer to  H. Lipson & M. Kurmar’s  ‘Fabricated: the new world of 3D printing’. Wiley. 2013). Selective extrusive printers in essence squirt, squeeze or spray pastes or powders through nozzles, syringes and funnels of all sizes to build up objects by depositing materials in layers. Selective binding printers by contrast, fuse, bind or glue materials together, again in a layers. The aforementioned technologies can, in one sense, be seen as producing analogue printing or additive manufacturing outputs using digital controllers. Currently at the cutting edge is true digital assembly using pre-manufactured physical objects. We can think of them as Lego blocks. However, precise assembly of billions of small physical voxels made in different and multiple materials remains a huge computational and fabrication challenge.  Of course, hybrids, deploying multiple print heads, deploying various different fabrication methods, could also be configured. Lipson and Kurmar summarise the evolution of additive manufacturing as three episodes of gaining control over physical mattercontrol over geometry, composition, and behaviour. First is an unprecedented control over the geometry, or shape, of objects. 3D printers can already fabricate objects of almost any material in any shape. Next is control over the composition of matter. We have already entered into this new episode where we go beyond just shaping external geometries to shaping the internal structure of materials with unprecedented fidelity, with the possibility of printing multiple materials including  ‘entangled components’ which can be co-fabricated simultaneously. The final stage is control over the behaviour of materials, where they envisage programmable digital materials – made of discrete, discontinuous units – which are designed to function in a desired way, such as spongy, transparent, rhinoceros-shaped, in shades of grey and blue – perhaps even embedded with nano devices. Voxel-based printing affords the notion of different types of physical voxels. Imagine, if you will, a library of archaeologically-defined material voxel types. Control over shape provides a bridge between existing 3D modelling formats and the ability to re-purpose them as 3D printed physical objects. Existing point clouds, terrain and solid models,indeed any system that can output STL format files can be 3D printed. By way of example, a 3D-printed map of the cone, crater, and summit of Mount St. Helens, Washington, USA, is available on Shapeways.com in three sizes!  Geologists are already 3D printing stacks of geology (i..e., stratigraphy) from north eastern GermanyAlthough these examples produce solid objects made only in a single material, with the same density throughout, they nevertheless communicate in a very tangible fashion. In fact, makers print all kinds of materials: from bread dough, chocolate, and other food-based materials with their pronounced olfactory characteristics (which, incidentally, introduces another cross-sensory modality into the mix), to gypsum, sand, soil, terracotta, metal alloys, plastics and polymers. At a somewhat higher level of technological sophistication, and, commensurately funding, modern industrial additive manufacturing technologies span a wide spectrum of applications across a very broader range of scales: from bioprinting living ink; replacement body parts and prosthetics; manufacturing textiles; ceramics; glassware; jewelry; furniture; weapons; vehicle components: and innumerable parts and fixtures, including 3D printer components. Crucially, they can also combine multiple entangled materials. Stepping back and opening the aperture of the nozzle somewhat,  let’s look at some more examples at a much larger scale. For example, Midwest Studios 3D printed a highly detailed architectural model for a new Carmelite foundation, designed as a classic French gothic monastery, in Wyoming, USA, using the architect’s CAD files. In Europe, Hansmeyer and Dillenburger, Swiss architects, created and 3D printed an ultra-modern, gothic-like, human-scale, immersive space dubbed the ‘Digital Grotesque’.  Both NASA and the European Space Agency are exploring the feasibility of building future moon-bases using fabricators exploiting local materials (i.e., regolith or lunar soil). Of course, at the moment, these projects require the use of (crucially) terrestrial simulants, in other words materials with the same necessary material properties.Becoming more speculative, more aspirational, let’s now explore some facets of additive manufacturing pertaining to materialisations of virtual archaeologies that might come to be. As additive manufacturing evolved from producing primarily single-material, homogenous shapes to producing multi-material geometries in full colour with functionally graded materials and microstructures, it created the need for a standard interchange file format that could support these powerful new features. The response was the Additive Manufacturing File format (AMF), an open standard for describing objects for additive manufacturing processes such as 3D printing. What is striking about the AMF format is that it encapsulates the typical recording sheet used on a modern archaeological excavation, but does so in much finer spatio-compositional (i.e. both macro-morphological and micro-morphological) detail. Image If we did recast our recording method to generate contexts described in an AMF-like format, we suggest that archaeology would be a step closer to aligning the virtual and physical worlds, and a step closer towards the possibility of rematerialising archaeological entities found in the field. What is to stop us from recording our excavations in such a way so as they can be refabricated? Current methods are clearly deficient. Here, by the way, we are not suggesting that all excavation should be 3D printed. We submit that if we recorded in such a way that we could rematerialise, or refabricate, our excavations in 3D then we would have improved substantively our practice. Some will argue that current procedures are adequate for current needs. We counter, that in a uniquely destructive discipline, are we not ethically obliged to strive for superior recording practices? We contend that AM provides a credible challenge to traditional archaeological practices (e.g.in recording). With this in mind, we call for disciplinary grand challenge for this generation of archaeologists, to fabricate an excavation, that is an excavation – rematerialised geometrically and compositionally accurate – whereby the curious can explore iteratively, reflexively, and comprehensively, the disaggregation and reassembly of archaeological entities encountered through archaeological intervention in such a manner as to engender a constant, multivalent, hermeneutic cycle between analysis and synthesis. We envisage that in striving to meet this challenge, the discipline will establish elements of an exemplary platform for strategic innovation, affording the development, and structured introduction of innovative and distinctly archaeological approaches through technology. In so doing we create a catalyst for increased innovation, strength of purpose, and direction in digital archaeology.