Add Some Digital to your Greek and Roman Archaeology Class!

With the word “syllabus” trending among my friends, I thought I might advertise an offering from my press. Last winter, we published a slim volume called Visions of Substance: 3D Imaging in Mediterranean Archaeology edited by myself and Brandon Olson. 

The volume is a nice little critical reader on the recent state of 3D imaging in Mediterranean archaeology. Thinking back to my Greek and Roman archaeology courses, I am now struck by how little we discussed technology or even technique in those courses. We mostly considered the architecture present important sites, basic typologies and chronologies, and some big picture themes in the history of the discipline. Today, of course, Greek and Roman archaeology classes are very different. Not only do we expect our students to know something about a range of methods (from open area excavations to intensive pedestrian survey) and methodologies (New Archaeology, Behavioral Archaeology, post-processual archaeology, and increasingly the debate over agency in archaeological practice), but also some familiarity with the use of technology (ranging from carbon-14 dating to GIS, databases, and photogrammetry) and incorporating some basic discussion of post-ancient archaeology. Needless to say, John Bintliff’s recently published survey of Greek archaeology (blogged about here and here) is a very different book than, say, William Biers’ crusty olde (er, venerable) The Archaeology of Greece or John Pedley’s Greek Art and Archaeology.

The upside of this is that our average field school student at the Western Argolid Regional Project knows a good bit more about archaeology as a discipline than I did as a junior or senior Latin major (or even as an M.A. student with a growing interest in the material culture!). At the same time, Greek and Roman archaeology courses have become more and more difficult to teach as no one textbook or survey introduces students to full scope of Mediterranean archaeology. So supplemental readings are a must.

Visions of Substance is a perfect supplemental reading for a Greek or Roman archaeology class. It is an up-to-date treatment of 3D imaging practices in “old world” archaeology with both practical examples of how the introduction of low cost 3D imaging technology is changing archaeological practice in the field and essays dedicated to the larger theoretical implications of these practices. The articles are written by scholars who are active in the field and leaders in the various aspects of digital archaeology and publishing.  Finally, and most importantly, it’s free and available for download here or here. Or, if you really like the smell of newly printed books, you can get a paper copy here.

Visions of Substance CoverALL loosefront

There are several additional readings available online here.

Here’s the table of contents:

1. Introduction
Brandon R. Olson 1

THEORY
2. 3D Imaging in Mediterranean Archaeology: What are we doing, anyway?
James Newhard 9

3. A Discussion of the Analytical Benefits of
Image Based Modeling in Archaeology
Brandon R. Olson and Ryan A. Placchetti 17

4. The Work of Archaeology in the Age of Digital Surrogacy
Adam Rabinowitz 27

5. Three- and Four-Dimensional Archaeological Publication
Andrew Reinhard 43

PRACTICE

6. Closing Gaps with Low-Cost 3D
Sebastian Heath 53

7. 3D Models as Analytical Tools
Ethan Gruber 63

8. Three Dimensional Field Recording in Archaeology: An Example from Gabii
Rachel Opitz 73

9. Photogrammetry on the Pompeii Quadriporticus Project
Eric Poehler 87

10. 3D Reconstruction of the Renaissance Bastion at the Langenbrücker Gate in Lemgo (Germany)
Guido Nockemann 101

11. Bringing the Past into the Present: Digital Archaeology Meets Mechanical Engineering
Brandon R. Olson, Jody M. Gordon, Curtis Runnels, Steve Chomyszak 107

About the Authors 113

Punk Archaeology Project Update

It’s been just over 200 days since The Digital Press at the University of North Dakota published their inaugural volume: Punk Archaeology

Since that time, the book has been cited twice. Once in Koji Mizoguchi, “A Future of Archaeology,” Antiquity 89 (2015), p. 20: “”Moreover, we should not be too bothered by the existence of ‘established’ media and the media hierarchy. High- quality e-books (e.g. Caraher et al. 2014)…”

And once by Sara Perry in her contribution to the Alison Wylie and Robert Chapman, Material Evidence: Learning from Archaeological Practice. (Routledge 2015): “Crafting Knowledge with (Digital) Visual Media in Archaeology”.

The book has been downloaded well over 1000 times (and likely about twice that) via my blog and viewed over 5000 times on Scribd. The blog post dedicated to the book has been viewed 3,800 times. The book is available for purchase on Amazon, but we’ve only sold around 50 copies

According to Shawn Graham and Ed Summers, the link for Punk Archaeology was the second most tweeted link from this past week’s Society for American Archaeology meeting, and this has accounted for about 5% of the book’s total downloads. 

In constrast, the second book from the press, Visions of Substance: 3D Imaging in Mediterranean Archaeology. (2015) has about 100 downloads over the past 100 days and 1200 views on Scrbd. The webpage has been viewed about 270 times. My hope is that this book becomes a bit more popular in the fall when it could be a useful, accessible, (and free) addition to a Mediterranean archaeology class. 

Overall, I’m pleased with the performance of the first two books from The Digital Press! If you haven’t checked either book out, please do!

Visions of Substance: The Dead Tree Version

I’m very pleased to announce that the paper version of Visions of Substance: 3D Imaging in Mediterranean Archaeology is now available on Amazon.

Visions of Substance CoverALL loosefront

It is a little more expensive than I would have liked at $24.00, but still within the acceptable range for academic books. It’s in color.

And, while I’d love for some folks to buy paper copies of the book and get them into their libraries. Everyone can always enjoy the free, digital version.

Visions of Substance: 3D Imaging in Mediterranean Archaeology: The Book

It is my great pleasure to release Visions of Substance: 3D Imaging in Mediterranean Archaeology edited by Brandon R. Olson and William R. Caraher with contributions by James Newhard, Adam Rabinowitz, Andrew Reinhard, Sebastian Heath, Ethan Gruber, Rachel Opitz, Eric Poehler, Guido Nockeman, and Brandon Olson with Ryan Placchetti, Jody M. Gordon, Curtis Runnels, and Steve Chomyszak.

Visions of Substance CoverALL Jan25

As readers of this blog know, these contributions began as a series of “3D Thursday” blog posts, but soon took on a life of their own as citations in scholarly publications and reading assignments in classes around the world. This volume consists of expanded and refined versions of many of the 3D Thursday papers with a new introduction. We feel confident that this is the first accessible primer to introduce both the theory and practice of 3D imaging in a Mediterranean and European archaeology. This slim volume is ideally suited for classroom use particular in Mediterranean archaeology classes which have tended to focus less on the technologies of archaeological work and more on formal concerns.

Best of all, the book is available for free and open access. So, please, download a copy, share the link to this page, and spread the word. Since The Digital Press at the University of North Dakota has no marketing wing, no budget, and no staff (and makes no profit or money!), I need you, dear readers, to help spread the word about our books. So please, tweet, Facebook, Ello, email, SMS, and otherwise circulate a link to this blog post!

For those of you who prefer your books in all three dimensions, a paper copy is available on Amazon for the low, low price of $24.

From the back of the book:

With the advent of low-cost and easy to use 3D imagining tools, the discipline of archaeology is on the cusp of a major change in how we document, study, and publish archaeological contexts. While there are a growing number of volumes dedicated to this subject, Visions of Substance: 3D Imaging in Mediterranean Archaeology represents an accessible and conversational introduction to the theory and practice of 3D imaging techniques in a Mediterranean and European context.

Original published as series of popular blog posts, the articles in this volume maintain their energetic and approachable tone, but now have full citations and an expanded introduction.

This is the second publication of The Digital Press at the University of North Dakota. The first book, Punk Archaeology is available as a free download here and on Amazon.

Update on The Digital Press: Booming Bakken and 3D Archaeology

The post-Punk Archaeology months have been relentlessly busy here at The Digital Press at the University of North Dakota, but now things have advanced enough to communicate an unofficial update on various projects.

We now have a full group of contributors to the Bakken Goes Boom book project and have prepared the book to send out for peer review. The line-up might change a bit here and there, but this what the table of contents looks like right now.

P1090200

Prologue

SWEET/CRUDE
Heidi Czerwiec

Introduction

Booms, Busts, and the Bakken
K. Conway and W. Caraher

Booms

The Paradox of Plenty: Blessings and Curses in the Oil Patch
Karin L. Becker

Revisited Frontiers: The Bakken, the Plains, Potential Futures, and Real Pasts
Sebastian Braun

Unpackaging Boomtown Tropes: Insider/Outsider Dynamics in North Dakota’s Oil Patch
Ann Reed

Booms and Busts: Haunting Memories in the North Dakota Oil Boom
Joshua E. Young

Health

Public Discourse on the Rise and Regulation of the Illicit Sex Trade During North Dakota’s Economic Booms
Nikki Berg Burin 

Oil Booms and Babies! Birth and Women’s Health Professionals Explain the Challenges of Western North Dakota’s Oil Boom
Heather Jackson

Doctors Wanted: How the Bakken Changed North Dakota Health Care Delivery
Jessica Sobolik

Nowhere to Run: How the Bakken Oil Boom Further Endangers Domestic Violence Survivors
Laura Tally

Media

Covering the Boomtown: How Mediated Communication Has Shaped Life in the Bakken Oil Region
Angela Cary

The Media Goes Boom
Amy Dalrymple

Cowboy Logic, For the Drill
Ryan Taylor

BAKKEN BOOM! Artists Respond to the North Dakota Oil Rush
Rebecca A. Dunham

Photographing the Bakken
Kyle Cassidy

Habitats

Notes from the Global Hinterlands: What It Feels Like to Be Global In North Dakota
Kyle Conway

Extractive Industries and Temporary Housing Policies: Man Camps in North Dakota’s Oil Patch
Bret Weber
Carenlee Barkdull

100 Miles of Wild: North Dakota Badlands Transect
Richard Rothaus, North Dakota University System
Simon Donato, Adventure Science
Melissa Rae Stewart, Adventure Science

The Archaeology of Man-Camps: Contingency, Periphery, and Late Capitalism
William Caraher  

Epilogue

~~~

I am also putting the final touches on the layout of the 3D Thursday book which we’re calling Visions of Substance. This was delayed as the press reorganized its staffing, but the book will appear and soon. What’s prompted this is tips from quite a few colleagues letting me know that articles from the blog are appearing in bibliographies. In the interest in creating a more archival and persistent citation for our contributors. So, progress is slow but steady and hopefully by the holidays, we’ll have a completed manuscript.

We’ve started looking at some cover designs as well. These are both just concepts, but I like the second option much more.

COVER OPTION 1

 

COVER OPTION 2

3D Models as Analytical Tools

This is the fourteenth in a series of posts exploring 3D modeling in Mediterranean and European archaeology. For more in this series click here. We hope these papers will start a discussion either in the comments of the blog or on Twitter using the #3DMedArch hashtag.

Ethan Gruber, American Numismatic Society

3DThrusday

Several years ago, when I was still a graduate student at the University of Virginia, I took part in a sort of Digital Humanities speed dating event hosted by the Scholars’ Lab, for whom I was employed as a web developer at the time. This event was geared toward creating connections between technologists and humanists at the university. I remember a brief encounter with two archaeologists in the Anthropology department (which was separate from my own Classical Archaeology program, which was part of Art History department) who saw only dubious benefit of 3D within the discipline. Models were seen by my colleagues as more of a sexy technological endeavor with little or no scholarly application. I discussed with them some of my own work in lighting simulation of 3D reconstructions, similar to the work by recently undertaken by Bernie Frischer and John Fillwalk on the solar interaction between the Horologium Augusti and the Ara Pacis, and so I hoped they developed a greater respect for the technology after enhancing their understanding of it.

We have seen in previous blog posts the value of 3D models in archaeological documentation and pedagogy, and so I wanted to discuss the value of architectural models as scholarly tools, enabling us to visualize the built environment and test hypotheses in ways that were previously impossible. My aim in this post is not necessarily to detail the results of these simulations (since you can find open access papers about most of these projects), but rather the provide a synopsis of the thought processes which go into creating the reconstructions and the evolution of my own sunlight simulation methodology, which has grown more sophisticated over the years.

The House of the Faun

My first foray into lighting simulation was purely accidental. In 2008, I used Autodesk Maya to create a 3D model of Pompeii’s House of the Faun, one of the largest and best known houses in the city. The model was created for a graduate seminar taught by John Dobbins to test hypothetical sight lines in a typical Italian atrium house. Sight lines are often presumed to be an integral part of Roman architecture. Architectural historians quite often depend on two dimensional plans to formulate their hypotheses. In theory, the open doors of the atrium house would invite passersby to gaze inside, revealing an architectural and social hierarchy of sorts: one may see the gardens beyond the tablinum, but may only enter this space if he or she is of higher social status, invited by the paterfamilias into this more intimate environment. The House of the Faun is a more special case, for just beyond the peristyle is the exedra containing the famous mosaic of Alexander the Great, and beyond this is yet another, larger peristyle. As it turns out, the sight line analysis of the 3D model of the house reveals it is basically impossible to see the exedra from the street, when basing the model upon the standard reconstructions found in printed illustrations.

FIG1 faun85Figure 1
View from the fauces to the Alexander exedra in the House of the Faun

Near the end of the semester, I happened upon a Maya script written by a lecturer of architecture at TU Delft, Thijs Welman, which allows a user to input the latitude and longitude of the structure, as well as the precise minute in time (back to 2000 B.C.), in order to accurately set the model’s sunlight angle. Once the angle is set, the model can be rendered with physically accurate light and shadows. I corresponded with Thijs briefly several years ago, and he was surprised that his script had found its way into the hands of an archaeologist–it had merely been intended to accurately render sunlight in the models of architecture students. He even extended the script, by my request, to animate the sunlight entity in Maya, enabling the rendering of timelapse videos.

I proceeded to render the exedra and the mosaic contained within on the equinoxes and solstices of 100 B.C., the approximate date of the mosaic’s installation. In the summertime, the angle of the sun was high enough that the mosaic was completely enshrouded in shadow. In the winter, however, the low sun projected six long shadows across the mosaic, certainly not an ideal viewing condition. 

FIG2 faun87Figure 2
About noon, December 21, 100 B.C.: commonly accepted reconstruction. Click image for walkthrough and timelapse animation.

When John Dobbins and I went to Pompeii the following summer (2009), we went into the House of the Faun and began to take note of peculiar architectural features which ultimately led us to conclude that when the new Roman overlords colonized Pompeii following the Social Wars, the new Roman patron of the house planned serious renovations of the peristyle, installed the exedra, the Alexander mosaic, and removed several columns and part of the portico to enhance the experience of encountering the space. For further details, please see our paper, presented at CAA in 2010.

FIG3 faun88Figure 3
About noon, December 21, 100 B.C.: alternate reconstruction.

Timelapse videos are available for both the summer and winter solstices.

The House of the Drinking Contest

Also in 2009, I began working on a reconstruction of the House of the Drinking Contest, a late Severan period house in Seleucia Pieria, the port city of Antioch (also published with Dobbins in the proceedings of CAA 2010). There were two purposes for this model: 1) test John’s sight line hypothesis published in Antioch: A Lost Ancient City (2000, ed., Christine Kondoleon) and 2) import images of the house’s elaborate mosaics into the model and apply/improve the lighting simulation methodology first tested on the House of the Faun to recontextualize the artworks–to experience them in the same environment that the ancient inhabitants of the house once (theoretically) experienced them. It was during this project that I began delving more deeply in the technological and theoretical aspects of the simulations and found that these methodologies had been applied first in 1994 by Simon Ellis (published in the fourth TRAC proceedings) and in later publications. Ellis’ methodology has been tremendously influential on my own scholarship, and I consider him to be one of the true pioneers in the adaptation of 3D models to archaeological research. The conclusions that he reached in his houses were quite similar to my own in the House of the Drinking Contest: that the setting sun in the spring and summer months shone through large doors of the triclinium, illuminating a grand central mosaic. It is at approximately this moment that guests would be gathered by the patron to take part in the symposium, with the most brilliant work of art illuminated with its glass and polished stone tesserae visible to all in a way that would otherwise never be visible earlier in the day or other times of year.

FIG4 render112Figure 4
Triclinium: June 21, A.D. 230, 6pm.

FIG5 planFigure 5
Plan of the House of the Drinking Contest

With respect to sight lines, Dobbins hypothesized that irregular intercolumniations within the colonnade bordering on the north side of the courtyard allowed for direct views from rooms on the north side of the house to the south. But what lay south? The archival photographs from the 1930s provide some glimpse, but by some stroke of luck, I was able to find a georeferenced photograph in Panoramio (discovered through Google Earth) of the same viewpoint taken from within one or two hundred meters from the site. Incorporating this photo into the model, I was able to simulate this hypothetical view through picture windows, glancing toward the shoreline of the Mediterranean and Mount Casius beyond. I have subsequently found a plethora of literary and archaeological examples of views to mountains and seas. But in archaeology, as we know, context is everything. How exactly do we know that there wasn’t a structure directly south of this house blocking this view? We don’t know for certain, but we can be reasonably sure this was not the case, based on the topography. The House of the Drinking Contest and those those houses built to the east and west were built on a terrace–the land sloped downward to the south, toward the sea. So while there may have been more houses to the south, they would have been lower to sea level, and therefore unlikely to have obstructed the view from this house. I believe this is an important point to drive home to anyone modeling reconstructions for scholarly purposes: artifacts must be placed back into context within the architecture, but one needs to take into consideration the larger topography surrounding the architecture. How do the walls and roofs affect the illumination of the mosaics? How does the natural or urban environment interact with the house itself?

FIG6 render121Figure 6
View toward the sea and Mount Casius to the south.

The Temple of Artemis at Ephesus

The final test case for 3D as a platform for scholarly analysis I would like to discuss (briefly) is a reconstruction of the Temple of Artemis at Ephesus. I modeled this in a graduate seminar on Anatolian archaeology to test a hypothesis postulated by Anton Bammer that one could view the epiphany of Artemis from within the temple: a sight line from the central pedimental window, toward and above the rear wall of the altar, to the cult statue below.

FIG7 fig17 altar view linesFigure 7
Witnessing the epiphany of Artemis from the pedimental windows.

While this may have been possible in the Archaic temple built by Croesus in 550 B.C., it would not have been possible in the 4th century temple, based on archaeological measurements. I applied the sunlight simulation methodology to observe the temple at different times of day throughout the year, but nothing particularly notable stood out. Unlike in the House of the Faun, where only the walls and roofs of the house affect the lighting within it, a structure of the size of this temple is largely unaffected by the built environment surrounding it. There was, however, potential for the physical topography to affect the lighting of the temple. The Austrian Archaeological Institute was gracious enough to provide me with their 10 meter resolution Digital Elevation Model data for Ephesus. To the southwest of the temple (between the temple and the Hellenistic/Roman city) lay the mountain, Panayirdağ. It was necessary to observe the interaction between this mountain and the sunlight, and in the waning hours on the winter solstice, shadows cast by the mountain fell upon the temple. It is not apparent that the architects of the temple took into deliberate consideration the sun’s effect on the structure, unlike those who designed the Augustan monuments in the Campus Martius in Frischer’s and Fillwalk’s project.

FIG8 sight lineFigure 8
Hypothesis applied to the reconstruction

Conclusions

Three dimensional models and simulations have enormous potential in furthering archaeological scholarship. They enable us to test hypotheses that could otherwise never have been examined, to observe the environmental conditions and context in which artworks and artifacts were placed in their own time, and, furthermore, formulate ideas that would never have been imagined by our predecessors before the digital age. John’s and my work on the House of the Faun is an example of this, I think. Simulations within the 3D reconstruction altered our perception of the ruins, and the next time we visited them, and we developed a different interpretation of the evidence.

The final issue that must be noted is that everything I have discussed is somewhat theoretical. While sunlight angles themselves are grounded in mathematical fact, reconstructions of ancient architecture are inherently theoretical. We create models which are plausible, based on data we have available, but these data are often incomplete or confusing. Thus, the simulations are not absolute truth, but rather a potential explanation of the past. The flexibility of 3D models allows us to address alternative scenarios based on new evidence or interpretations.

References

Ellis, Simon. 1994. “Lighting in Late Roman Houses.” In TRAC 94: Proceedings of the Fourth Annual Theoretical Roman Archaeology Conference, held in Durham, 65-72.

——–. 2000. Roman Housing. London: Duckworth.

——–. 2007. “Shedding Light on Late Roman Housing.” In Housing in Late Antiquity, edited by
Luke Lavan, Lale Özgenel, and Alexander Sarantis, 283-302. Leiden, Boston: Brill.

Gruber, Ethan and John Dobbins. “Illuminating Historical Architecture: The House of the Drinking Contest at Antioch.” In the proceedings for Computer Applications and Quantitative Methods in Archaeology 2010 held in Granada, Spain 6-9 April, 2010.

——–. “Modeling Hypotheses in Pompeian Archaeology: The House of the Faun.” In the proceedings for Computer Applications and Quantitative Methods in Archaeology 2010 held in Granada, Spain 6-9 April, 2010.

Lippolis, Isabella Baldini. 2007. “Private Space in Late Antique Cities.” In Housing in Late Antiquity, edited by Luke Lavan, Lale Özgenel, and Alexander Sarantis, 197-237. Leiden, Boston: Brill.

 

Bringing the Past into the Present: Digital Archaeology Meets Mechanical Engineering

 This is the thirteenth in a series of posts exploring 3D modeling in Mediterranean and European archaeology. For more in this series click here. We hope these papers will start a discussion either in the comments of the blog or on Twitter using the #3DMedArch hashtag.

3DThrusday

Brandon R. Olson (Boston University)
Jody M. Gordon (Wentworth Institute of Technology)
Curtis Runnels (Boston University)
Steve Chomyszak (Wentworth Institute of Technology)

Introduction

New technologies are making it possible to reinvestigate what ancient human life was like in earlier historical eras in ways that are more ethical, safe, cheap, and exact than ever before. One of the most groundbreaking technologies harnessed to analyze archaeological objects and landscapes is 3D modeling and, consequently, 3D printing. Over the last two years, as 3D modeling software, techniques, and printers have rapidly become cheaper and more user friendly, the adoption of 3D technologies in archaeological research has literally exploded with new projects appearing on a daily basis, as demonstrated by numerous contributions to this volume. Although archaeologists began printing objects created with 3D laser scanners a few years ago (Kuzminsky and Gardiner 2012; Niven et al. 2009), the speed of technological development focusing on modeling and printing in 3D presents another tool for the archaeologist’s expanding digital toolkit. Our purpose here is to present a preliminary study of the applicability of image based modeling, as opposed to laser scanning, for 3D printing in archaeology using three printing formats (ABS plastic, powder, and resin). The artifact we tested was an Acheulean handaxe (Figure 1A), the same artifact presented in Olson and Placchetti’s (2013) contribution.

Figure 1Figure 1: A): The modeled Acheulean handaxe; B): Printed handaxe using ABS plastic; C) Printed handaxe using powder; D): Printed handaxe using resin.

The Problem

Efforts to illustrate accurately the form and appearance of chipped stone tools of flint, obsidian, and other siliceous rocks have been ongoing since the mid-nineteenth century when the first flaked stone artifacts were recognized as the artificial products of early human handicraft. Photography has only rarely been employed for illustrating stone tools because of the reflective surfaces of the rocks that were used to manufacture the tools, which make it difficult to light the specimens adequately to bring out the texture. There was also the problem of the depth of field, which made it difficult to focus both on the center and the retouched edges of the stone tool in the same photograph. Finally, the three dimensional form of the artifact was difficult to evaluate in the flat, two dimensional world of reflective analog photography.

These difficulties were overcome, at least partially, by the use of measured line drawings that included the outline of the stone tool, the pattern of the scars on the surface left by the removal of flakes in the reduction and retouch stages of artifact manufacture, and the use of shading lines in the flake scar outlines to suggest the volume of the artifact and the texture of its surface as they might have appeared if the artifact was lit obliquely from the upper left. These conventions for making two dimensional technical line drawings were established by French and English archaeologists in the 1860s, and have been used in publications ever since to enable readers to “see” artifacts like the Palaeolithic handaxes that convinced early archaeologists of the antiquity of humans in Europe. There was even a chromolithographic plate illustrating a handaxe in a publication from 1865 that attempted to show the color of such an artifact in a realistic manner.

As a consequence of the slow evolution of the methods of illustration and reproduction of stone tools, the demand for a more flexible method for reproducing the appearance of stone tools has long been desired. This need is now being met by the combination of digital photography and 3D printing. Here we discuss our own successful experiments to photograph original artifacts, in this case early Palaeolithic handaxes like those that were the subject of the first attempts at artifact illustration in the nineteenth century. We believe that this method, which uses commercially available software and hardware and does not require prolonged technical training or expensive scanners, can be readily and inexpensively deployed to the field, whether the museum, the laboratory, or the excavation site, allowing the rapid and accurate 3D imaging and reproduction of stone tools in a matter of hours. In our view this is the most significant advance in the illustration of stone tools to have been made in over the past 150 years.

The (Abbreviated) Process

The process began by taking 95 photographs at five different angles using a tripod and a rotatable surface, an effective photographic method that has been successively tested in the field (Olson et al. 2013). The object was photographed with an 18 MP Canon Rebel T4i with an 18–135 mm lens. The photos were then loaded into PhotoScan to first generate a tessellated 3D point cloud, then a monochromatic 3D model, and finally a fully photorealistic textured model. The textured model was then exported as an .obj file and brought into Meshlab for scaling and conversion to a .stl file for printing. With the assistance of Mechanical Engineering and the 3D Printing Lab at Wentworth Institute of Technology in Boston, we printed the handaxe using three types of 3D printers (ABS plastic [Figure 1B], powder [Figure 1C], and resin [Figure 1D]).

Figure 2Figure 2: Steve Chomyszak using the uPrint 3D printer (ABS plastic)

In the end, it took approximately 4 hours to fully model the Acheulean handaxe with an image based modeling technique and depending on the desired printing media, up to 7 hours for each print. From a costs perspective, the modeling of the objects required a digital SLR camera, a tripod, and a professional license of PhotoScan ($549 with the educational discount). Printing costs varied by printer type, but costs incurred for materials were as follows: ABS plastic ($58.55) (Figure 2), powder ($36.06), and resin ($120.77). It must be noted, however, that the pricing provided is based on Wentworth’s 3D Printing Lab guidelines, which only include material replacement costs and not auxiliary fees that one might encounter in a commercial setting. 

Implications

After critically evaluating each model, it was clear that certain 3D printing formats were more conducive to retaining minute lithic characteristics than others. The powder model, unless immersed in a durable coating, is simply too fragile for continued handling. Although the model retains faint horizontal lines, which are byproducts of printing, the ABS plastic model retained the physical characteristics that a lithicist would expect to see in a reproduction. Baker (2013) and Forte (2013) briefly note the benefits of ABS plastic printing in this volume. It is the resin model that is the spitting image of the original handaxe in both its fidelity in retaining lithic features and its physical weight and feel.

This entire process has allowed us to think of all the ways that the combination of inexpensive image based modeling and printing could revolutionize existing modes of archaeological analysis, dissemination, and education. This process now makes it possible for an archaeologist with little training to obtain a digital camera, shoot a host of photos of an object, process the images in a user-friendly and inexpensive photogrammetry program, and then print a 3D model (printing costs varying between $35 and $125 depending on the material type and artifact size), all within a day’s work. It is completely revolutionary as it literally brings the technology of the Stone Age back to life and solves a 150-year old problem of lithic display.

3D Archaeology at Çatalhöyük

 This is the twelfth in a series of posts exploring 3D modeling in Mediterranean and European archaeology. For more in this series click here. We hope these papers will start a discussion either in the comments of the blog or on Twitter using the #3DMedArch hashtag. 

3DThrusday

Maurizio Forte, Duke University

Introduction

Digital documentation and visualization in archaeology include digital applications of computer graphic rendering and simulation involving data, models and spatial information produced by different integrated technologies of data capturing, virtual reconstruction and visual communication (Forte 2010; Forte and Kurillo 2010; Forte and Siliotti 1997; Forte 2012). In the last decade the use of digital technologies on archaeological sites has exponentially grown at different scales and for different purposes: GIS, mapping, 3D modeling, remote sensing applications and digital photogrammetry. A really revolutionary approach in the archaeological documentation (on and off site) has been the introduction of image modeling techniques (with software like, for example, Photomodeler and Photoscan) for 3D data recording by DSLR cameras. In short, the archaeological models are generated by the overlapping of a sequence of high-resolution digital photos taken by uncalibrated cameras (Forte 2012). The relevant increasing of digital resolution in SLR cameras (over 15-20 mp) has also allowed the achievement of very interesting results in terms of 3D accuracy, performance and speed of data processing. In fact, the application of entry-level, intra-site 3D-technologies has fostered the community of archaeologists to consider 3D not just an “expensive” option, but a very affordable facility, also for the production of additional documentation, such as maps, sections, profiles, volumetric analyses and so on with a high level of accuracy. For example, our tests at Çatalhöyük have demonstrated that in a 3D model of a Neolithic house (around 25 square meters) (generated by the software Photoscan) the accuracy is about 4-5 mm (Forte 2012).

Visualizing Çatalhöyük

Çatalhöyük is a Neolithic site located in Central Anatolia and it is considered one of the “first cities of the world” (fig.1). Excavated by James Mellart from the ‘60s and then from Ian Hodder from the 80s, Çatalhöyük has been for a long time as a special place for the experimental introduction of new methodologies and theoretical approaches in archaeology such as multivocality, post-processualism and, more recently, cyber-archaeology and new media (Hodder 1989; Hodder 1990; Hodder 2006; Hodder, et al. 2007). The site, dating from 7400-6000 B.C is made up of two mounds: Çatalhöyük East and Çatalhöyük West. Çatalhöyük East consists of 21m of Neolithic deposits. Çatalhöyük West is almost exclusively Chalcolithic (6000-5500 B.C.), located in a different position and showing evident social-cultural changes in the settlement and territory organization. The two mounds span 2000 years and show an impressive urban continuity though time whereas the house is the social-cultural-urban pattern of the system: ritual, domestic and symbolic space in the same time.

01Figure 1

Çatalhöyük was discovered in the 1950s by the British archaeologist James Mellaart (Mellaart 1967) and it was the largest known Neolithic site in the Near East at that time. Important events such as the domestication of plants, invention of pottery in connection with the large size and dense occupation of the settlement, as well as the spectacular wall paintings and other art forms that were uncovered inside the houses made it very famous internationally. The houses had no doors to the outside (main entrance from the roof), and the inhabitants buried their dead under the floors of their platforms. Despite several decades of study and excavation, the diachronic urban development of the site is still very controversial and it needs more studies and analyses in relation with the landscape and the symbolic, ritual and social use of the buildings. The site was inscribed in the UNESCO World Heritage list in 2012. 

The 3D-Digging Project

The 3D-Digging Project started at Çatalhöyük in 2009 with the intent to digitally record in 3D all the archaeological stratigraphy in some areas of excavation using an integrated approach (different devices and technologies) for virtually reconstructing all the process in desktop and virtual reality systems. The 3D documentation is not yet a standard in archaeology but it can change the hermeneutic outcome of an excavation since it is able to create new interpretations and research questions because of 3D connections, simulations and interactive modeling. A first experiment of 3D recording of ritual figurines by optical scanner (Nextengine; figs.2-3) started in 2009: the models were originally recorded in semi-automatic way by the scanner, then optimized in Meshlab and finally printed in three dimension (fig.3).

4Figure 2

5Figure 3

In this preliminary phase the project was aimed at the comparison and study of different kinds of laser scanners (based on different technologies and settings) in order to understand their performance in relation to the project goals (see table below).

Table 1 

The first questions/issues arising from this analysis were mainly focused on the level of accuracy and scale of representation for the models. Optical and time of flight scanners, in fact, have different performance and technical features. Optical scanners work in a range of microns (about 300,000 pts per second, the Minolta), time of flight scanners in a range of mm/cm. 

In the 3D-Digging Project the strategy was to make comparative testing involving optical, time of flight, and shift-phase scanners (see table 1) in order to understand the performance of the scanners and accuracy in relation to archaeological information. For example, details of stratigraphic surface or micro-morphologies are not visible by naked eye or with other means. For archaeological stratigraphy we have tested the Minolta 910 (optical), Trimble GX (time of flight), Trimble FX (shift-phase) and Faro Focus 3D (shift-phase). 

In 2010 the first experiment was undertaken with the Minolta 910 for recording all the excavation layers in a “midden” area (fig.4). “Midden” areas at Çatalhöyük correspond to accumulation of rubbish outside the living areas and can indicate social/collective activities made for different scopes (construction works, dedicated place for rubbish, etc.). The initial idea was to use an optical-triangulation scanner (Minolta 910) for stratigraphy in order to visualize and better study micro-layers (Shillito L.-M 2011), since they are not easily identifiable with an autopsic experience (figs.5-7).

6Figure 4

7Figure 5

8Figure 6

9Figure 7

In 2011, we have adopted two systems working simultaneously for data recording: a new time of shift-phase scanner (Trimble FX) and a combination of camera based software of computer vision and image modeling (Photoscan, stereoscan, Meshlab). The Trimble FX is a time of shift-phase scanner able to generate 216000 pt/sec and with a 360 x 270* field of view; it is a very fast and effective scanner with the capacity to generate meshes during data recording, so that to save time in the phase of post processing (fig. 8). The strategy in the documentation process was to record simultaneously all the layers/units in the sequence of excavation using laser scanning and computer vision. At the end of the season we have generated 8 different models of the phases of excavation by computer vision (3D camera image modeling, figs. 9-10) and as well by laser scanning (figs.11-13). All the 3D models were available on daily basis for interactive visualization and spatial analysis. The scheme below shows the principal features and differences between the two systems; laser scanning requires a longer post-processing but it produces higher quality of data. Computer vision allows to have immediate results and to follow the excavation process in 3D day by day but not with the same geometrical evidence of the laser scanner. 

10Figure 8

11Figure 9

12Figure 10

13Figure 11

14Figure 12

15Figure 13

The digital workflow for the computer vision processing is based on 1) photos alignment; 2) construction of the geometry (meshes) 3) texturing and ortophoto generation. The accuracy by computer vision measured in 2011 models was around 5 mm. The use of georeferenced targets on site was implemented for the automatic georeferencing of 3D models with the excavation grid. In that way all the 3D information recorded during the excavation is perfectly oriented and integrated with all the 2D maps, GIS layers and archeological data. The speed of this process has allowed daily discussions on the interpretation of the archaeological stratigraphy and on 3D spatial relations between layers, structures and phases of excavation. In addition, the excavation of an entire building (B.89) has allowed testing the system in one single context so that to produce a 3D multilayered model of stratigraphy related to an entire building. The excavation of a Neolithic house is an ideal case study for testing 3D data recording and puzzling of a multi-stratigraphic context since it is possible to visualize and investigate post-depositional and depositional phases related to the life and the abandonment of a building (construction works, foundations, rituals, domestic activities and so on). Moreover, the B89 is a quite big house, well-preserved and with a very interesting stratigraphy (fig.9).

The current workflow allows every team managing independently almost all the phases of digital data recording on site and to interpret the data directly in lab at the end of the day: by computer vision, 3D sketching, 3D visualization. The software used for 3D modeling is Meshlab, Photoscan, 3D Studio Max; for 2D mapping is ArcGIS, QGIS, OpenJump, Autocad, Meshmixer. All the 3D models are georeferenced and exportable in different spatial software and platforms. After 3 years of fieldwork, the digital workflow is robust and consistent: computer vision (shape from modeling) is undoubtedly the most effective, user friendly and robust technique in intra-site contexts. The fact that involves the use of standard digital cameras (from 8 to 24 Mpixels) and very low cost and open source software (Photoscan and Meshlab, QGIS), makes all the pipeline very portable and usable sharing the same technologies. At Çatalhöyük computer vision is typically used at intra-site level for data recoding of buildings, layers, units, features and burials (fig.14), while laser scanning also at inter-site scale.

17Figure 14

More specifically, the 2012 fieldwork season have involved different scales of data recording: artifacts by optical scanner (microns accuracy); stratigraphic units by computer vision (accuracy: 0.5-1 cm); buildings and features by time of phase laser scanning (accuracy: 3-5 mm); large scale models (South and North shelters) by time of phase laser scanners (0.5 cm). 

The systematic use of computer vision and 2D photogrammetry for data recording of burials was extremely successful for the osteologists’ team coordinated by Scott Haddow (fig.14). Indeed, in 2012 it was possible to record and reconstruct in 3D twenty-one burials with related 2D drawing of skeletons and other features (fig.14). In this case the digital workflow involves computer vision for the generation of 3D models, 2D and 3D georectification, 2D drawing of the burials in CAD (Librecad) and finally their implementation in ArcGIS as digital maps (raster-vector) and 3D models (3ds).

For the building 89, 3D data recording has followed the procedure of single context excavation: every 3D model was generated in relation to the identification and classification of stratigraphic units. Finally, all the 3D models of B89 were aligned and georeferenced (total 25 phases in 2011-2012)  in Meshlab and ArcGIS.

The DiVE – Duke Immersive Visualization Environment

The digital workflow established during the excavation was able to generate a relevant amount of data in the format of point clouds, 3D models, textures and metadata, all georeferenced in the same space. Interaction and use of 3D models are crucial for data interpretation on site but also during a simulation process during a lab session. A quite complicated issue concerns how it is possible to make all this digital process completely reversible. In other words: how can we browse layers, stratigraphy and artifacts in a virtual reality system? How can an immersive embodiment be used for a virtual digging? During the excavation all the data have been processed and visualized in Meshlab: this software includes in fact many tools for data processing, meshing, merging and visualization by layers. However a higher level of 3D processing was needed in order to better study the 3D connections of models and layers.

With this premise in mind, all the models made by laser scanners and computer vision have been optimized and implemented for the DiVE, the Duke Immersive Visualization Environment at Duke University (fig.15). The DiVE is a research and education facility dedicated to exploring techniques of immersion and interaction: it is the fourth 6-sided CAVE-like system in the United States (figs.15). The DiVE is a 3m x 3m x 3m stereoscopic rear projected room with head and hand tracking and real time computer graphics. All six surfaces – the four walls, the ceiling and the floor – are used as screens onto which computer graphics are displayed. The DiVE offers a fully immersive experience to the user, who literally walks into the virtual world. The user is surrounded by the display and can interact with virtual objects: stereo glasses provide depth perception, and a handheld “wand” controls navigation and virtual object manipulation. This digital immersive embodiment increases the sense of presence of the user in the virtual domain, fostering the identification of affordances and 3D connections, otherwise non visible in the real world.  

24Figure 15

The entire B.89 was virtually reconstructed in the immersive system including all the stratigraphic layers excavated in 2011-12. The handheld “wand” controls navigation allows interacting and browsing layers, models and artifacts in 3D, using a 3D menu. The tracking system connected with stereo glasses drives the visualization according to the head position of the user. In this way, the virtual exploration augments the sense of presence in the virtual environment. The first tests inside the DiVE concerning the visualization and interaction of the Neolithic house, B89, have been quite successful: the 6 sided CAVE rescale the virtual building in a very realistic way, giving the users a very immersive sense of space and the feeling to be in the mid of the excavation “pod”. The interaction with different layers and stratigraphy “from inside” creates a specific “archaeological” embodiment, where the users can discuss and see data/models in transparency (fig.15). In addition, the B89 was also virtually reconstructed as it is assumed it was originally with plaster, floor, decorations, roof and interior architecture. The virtual reconstruction overlays the structures of the building as they appear today by laser scanning recording. In this way it is possible to compare the potential original physiognomy of the building with the structures explored during the excavation.

Since the DiVE can host even 6-7 people simultaneously, it is possible to organize presentation for small classes or research working groups. Indeed, at Duke we started to schedule small groups  and classes discussions about principles of archaeological stratigraphy, architectural features of Neolithic houses, depositional and post-depositional events, also in preparation to the summer fieldwork.

Acknowledgments

Trimble Navigation, Scott Haddow, Stefano Campana, Gianfranco Morelli and all our students for their dedication and efforts in the excavation and in the participation to the 3D-Digging Project. Special thanks to Elisa Biancifiori, Francesca Paino and Matteo Pilati for their contributions to the success of the project.
First experiment of optical scanners (Minolta 910) on 3D stratigraphy : Fabrizio Galeazzi, UC Merced
Time of flight laser scanning data recording coordinated by Nicola Lercari, Duke University
Virtual preliminary reconstruction of B89 made by Rebecca Lai, Duke University
Computer vision and shape from modeling coordinated by Nicolo’ Dell’Unto, Lund University.

References

Barcelo J.A. De Castro, O., Travet ,D., Vicente, O.
2003 A 3d Model of an Archaeological Excavation O. De Castro, ed. Pp. 85-90, Vol. The Digital Heritage of Archaeology. Computer Applications and Quantitative methods in Archaeology Edited by M. Doerr & A. Sarris. Crete: Hellenic Ministry of Culture. Archive of Monuments and Publications.

Barcelo´, J.A., Vicente, O.,
2004 “Some problems in archaeological excavation 3D modelling.” Pp. 400-404, Vol. in: Ausserer, K.F., Borner, W., Goriany, M., Karlhuber- Vockl, L. (Eds.), Enter the Past: The E-way into the Four Dimensions of Cultural Heritage. Oxford: BAR International Series 1227. Archaeopress.

Benko, H., E. W. Ishak, and S. Feiner
2004 “Collaborative mixed reality visualization of an archaeological excavation. Mixed and Augmented Reality,” 2004. ISMAR 2004. Third IEEE and ACM International Symposium on, 2004, pp. 132-140.

De Felice G., Sibilano M., Volpe G. (Eds.)
2008 L’Informatica e il Metodo della Stratigrafia ed, Vol. Atti del Workshop Foggia: Edipuglia.

Donald, Merlin
1991 Origins of the modern mind : three stages in the evolution of culture and cognition. Cambridge, Mass.: Harvard University Press.

Doneus, M. Neubauer W.
2004 Digital Recording of Stratigraphic Excavations. BAR INTERNATIONAL SERIES 1227:113-116.

Doneus, M., Neubauer, W.
2005 “Laser scanners for 3D, documentation of stratigraphic excavations.” Pp. 193-246, Vol. in: International Workshop on Recording, Modeling and Visualization of Cultural Heritage. Ascona: Taylor&Francis.

Earl, G.
2007 “De/construction sites: Romans and the digital playground.” Pp. 1-11, Vol. In, Bowen, Jonathan, Keene, Suzanne and MacDonald, Lindsay (eds.) Proceedings of the Electronic Visualisation and the Arts. London: EVA Conferences International.

Forte, M.
in press in “Cyberarchaeology: a Post-Virtual Perspective,” Vol. in Humanities and the Digital. A Visioning Statement (David Theo Goldberg and Patrik Svensson eds.) . Boston: MIT Press.

—. 1995 “Scientific visualization and archaeological landscape: the case study of a terramara”. Pp. 231-238, Vol. Archaeological and Geographical Information Systems (ed. by G.Lock e Z.Stancic). London: Wiley Periodicals, Inc., A Wiley Company.

—. 2010 Cyber-archaeology. Oxford, England: Archaeopress.

Forte, Maurizio, and Gregorij Kurillo
2010 “Cyber-archaeology and met averse collaborative systems.”  Metaverse Creativity 1(1):7-19.

Forte, Maurizio, and Alberto Siliotti
1997 Virtual archaeology : re-creating ancient worlds. New York: H.N. Abrams.

Forte, Maurizio; Dell’unto, Nicolo; Issavi, Justine; Onsurez, Lionel; Lercari, Nicola
2012 3D Archaeology at Çatalhöyük.

Gibson, James J.
1979 The ecological approach to visual perception. Boston: Houghton Mifflin.

Hodder, Ian
1989 The Meanings of things : material culture and symbolic expression. London ; Boston: Unwin Hyman.

—. 1990 The domestication of Europe : structure and contingency in neolithic societies. Oxford, OX, UK ; Cambridge, Mass., USA: B. Blackwell.

—. 2006 The Leopard’s tale : revealing the mysteries of Çatalhöyük. New York, N.Y.: Thames & Hudson.

Hodder, Ian, and McDonald Institute for Archaeological Research.
2005a Changing materialities at Catalhoyuk : reports from the 1995-99 seasons. London: British Institute at Ankara.

— 2005b Inhabiting Catalhoyuk : reports from the 1995-99 seasons. 1 vols. Cambridge: McDonald Institute for Archaeological Research.

Hodder, Ian, McDonald Institute for Archaeological Research., and British Institute of Archaeology at Ankara.
2007 Excavating Catalhoyuk : South, North and KOPAL area reports from the 1995-99 seasons. Cambridge London: McDonald Institute for Archaeological Research ; British Institute at Ankara.

Katsianis, Markos Tsipidis Spyros Kotsakis Kostas Kousoulakou Alexandra
2008 “A 3D digital workflow for archaeological intra-site research using GIS.” Journal of Archaeological Science 35(3):655-667.

Kreylos, O.
2008 “Environment-independent VR development.” Pp. 901-912, Vol. In: G. Bebis, et al. (eds.): Advances in Visual Computing: ISVC LNCS 5358.

Kurillo, G., and M. Forte
2012a “Telearch – Integrated visual simulation environment for collaborative virtual archaeology.” Mediterranean Archaeology and Archaeometry 12(1):11-20.

Levy, T. E. Petrovic V. Wypych T. Gidding A. Knabb K. Hernandez D. Smith N. G. Schlulz J. P. Savage S. H. Kuester F.
2010 On-Site Digital Archaeology 3.0 and Cyber-Archaeology: Into the Future of the Past – New Developments, Delivery and the Creation of a Data Avalanche. BAR INTERNATIONAL SERIES 2177:135-153.

Mellaart, James
1967 Çatalhöyük : a neolithic town in Anatolia. London: Thames & Hudson.

Morgan, Colleen L.
2009 “(Re)Building Çatalhöyük: Changing Virtual Reality” in Archaeology. Archaeologies 5(3):468-487.

Petrovic V, Gidding A. Wypych T. Kuester F. Defanti T. A. Levy T. E.
2011 “Dealing with archaeology’s data avalanche.” Computer Computer 44(7):56-60.

Renfrew, Colin Scarre Christopher
1998 Cognition and material culture : the archaeology of symbolic storage. Cambridge, England: McDonald Institute for Archaeological Research.

Sanders, Donald
2011 Enabling archaeological hypothesis testing in real time using the REVEAL documentation and Display system. Sociedad Espanola de Arqueologoa Virtual.

Sangregorio, E., Stanco, F. and Tanasi, D.
2008 “The Archeomatica Project: Towards a new application of the computer graphics in archaeology,” Vol. In Scarano, V., Chiarra, R.D. and Erra, U. (eds.), Proceedings of Eurographics Italian Chapter Conference. Fisciano: Eurographics Association.

Shillito L.-M, Matthews W. Almond M. J. Bull I. D.
2011 “The microstratigraphy of middens: Capturing daily routine in rubbish at Neolithic Catalhoyuk, Turkey.” Antiquity Antiquity 85(329):1024-1038.

Tringham, Ruth Stevanovic Mirjana
2012 Last house on the hill: BACH area reports from Catalhoyuk, Turkey. Los Angeles, CA: Cotsen Institute of Archaeology Press.

Tsioukas, Vassilios, and Petros Patias
2003 “Low Cost 3D Visualization and Measuring “Tool” in the Service of Archaeological Excavations.” In Digital heritage of archaeology CAA 2002 ; computer applications of the quantitative methods in archaeology ; proceedings of the 30th conference, Heraklion, Crete, April 2002. M. Dörr and A. Sarris, eds. Pp. 119-124 %@ 960-214086-0. Athen: Archive of Monuments and Publications.

3D Modeling in Mediterranean Archaeology: A Table of Contents

Since for a good percentage of my readers this is Thanksgiving and a holiday, I’ll just offer a quick post today.

3dthrusday2

We have received almost all of the contributions for our little collection of articles on 3D documentation in Mediterranean archaeology. To make them a bit more accessible to our readers, I’ve created a table of contents and posted it as a page on my blog. You can get to it by the link on the left. 

Two or three more will appear over the next few weeks and I’ll update the table of contents as they go live.

If you’re in the U.S., enjoy your turkey day. To my international readers, I’ll begin posting 3D Thursday again next week.

3D Reconstruction of the Renaissance Bastion of the Langenbrücker Gate in Lemgo (Germany)

This is the eleventh in a series of posts exploring 3D modeling in Mediterranean and European archaeology. For more in this series click here. We hope these papers will start a discussion either in the comments of the blog or on Twitter using the #3DMedArch hashtag.

Guido Nockemann, Freelance Archaeologist, AMD Nockemann,

In the beginning of the 16th century up until the Thirty Years War, the city of Lemgo was turned into a Renaissance fortress with a rampart, trench and bastions – unfortunately it was never finished. The southern entrance to the city was a bastion bathed by the river Bega with an associated gate construction with rampart and outer bailey on the city side (fig. 1).

Pic 1 LennepstichFigure 1: The Langenbrücker gate on a copperplate print of Elias and Henry van Lennep, about 1663

During archaeological excavations from 2009 to 2011 in preparation for constructions of the Langenbrücker Gate, remains of a Renaissance bastion were uncovered. They uncovered the massive counter bearings of the former bridge, wall remains of the outer bailey, torwange, curbstones of the gate, remains of the foundation of the gate tower of the bastion, wall fragments of the northern part of the bastion and parts of the side walls (fig. 2 and fig. 3).

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Figure 2: Southern abutment of the bridge and wall remains of the bastion (picture: Guido Nockemann)

Pic 3 WiderlagerFigure 3: Northern abutment of the bridge (picture: Guido Nockemann)

To present the results of the excavation to the public in a better way a 3D reconstruction of the southwestern part of the town fortification of Lemgo was established. It is based on the archaeological finds of the excavation as well as on historic plans and records (fig. 4). The point of time presented is around 1646, the end of the Thirty Years War, because the majority of data comes from that period. The archaeological evidence, however, is problematic due to consistent constructions for over hundreds of years and the historic tradition is inconsistent. Historic drawings of the city are often idealized and do not necessary correspond to reality. Different illustrators at different points in time drew, to some extend, very different views of the city e.g. in roofing, variation and size of towers. Information from historic records and city maps were taken into consideration in establishing the model.

Pic 4 StadtansichtFigure 4: Detail of a cityscape of the city of Lemgo south, 1 Half of the 18th century

A scale floor plan was used as a base for the 3D model considering every data accessible. If there was more than one possibility to solve a problem of detailing, the most likely one was taken. Historic photographs of parts of the town fortification, still existing in the 19th century, were a huge help.

Overlapping old city maps with archaeological finds showed anomalies which can be explained by the inaccurate measurement methods of that time. If there were not any archaeological evidence for walls or buildings, their position had to be interpolated. While reconstructing the structures above ground, data from records and from drawings of the city could be used. As there are no hints to the materials used for the finishing of the fortification and buildings, no photorealistic textures were used in the model. With a button, the actual archaeological finds can be made visible in the 3D model (figs. 5 and 6).

Pic 5 3D RekonstruktionFigure 5: 3D reconstruction of the bastion and gate system at the Langenbrücker gate (graphic: Morris Viaden – Kleinkino / Medienproduktion)

Pic 6 3D Rekonstruction 2Figure 6: Detail of the 3D reconstruction (graphic: Morris Viaden – Kleinkino / Medienproduktion)

An introductory text is essential for the visitors to explain the basis for the reconstruction was established. The main problem with that is, to a scientist, a 3D model is just one way of interpreting finds, but the general public will take that model for “scientific evidence and truth”. It should be stressed in the description, that the model is just one possible appearance, even if it is a very likely one, of the fortification of the city of Lemgo.

References:

• Guido Nockemann (in press): Die 3D-Rekonstruktion der renaissancezeitlichen Festungsanlage am Langenbrücker Tor in Lemgo, in: Archäologie in Westfalen-Lippe

• Guido Nockemann (2012): Lemgo – Langenbrücker Tor; Ergebnisse der archäologischen Untersuchungen, Kampagnen 2010 / 2011 (Online-Presentation: http://www.lemgo.net/fileadmin/image/redakteure/planungsamt/Denkmalpflege/Ausgrabung_Langenbruecker-Tor_2012.pdf)

• Link to the 3D-Rekonstruktion: http://www.lemgo.net/fileadmin/image/redakteure/planungsamt/flash/lemgo3d.html