Digital Reconstruction of Archaeological Findspospabr.sweb.cz/dpJanPospisil.pdf · This thesis deals with the topic of digital reconstruction of objects and espe-cially its use in

MASARYKOVA UNIVERZITAFAKULTA INFORMATIKY

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Digital Reconstruction ofArchaeological Finds

DIPLOMOVÁ PRÁCE

Jan Pospíšil

Brno, jaro 2012

Declaration

Hereby I declare, that this paper is my original authorial work, which I haveworked out by my own. All sources, references and literature used or ex-cerpted during elaboration of this work are properly cited and listed in com-plete reference to the due source.

Jan Pospíšil

Advisor: MgA. Helena Lukášová, ArtD.

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Acknowledgement

I would like to thank my adviser MgA. Helena Lukášová, ArtD. for her pa-tience, overall support and accommodating approach. I also thank BerzovanAlexandru (Babes-Bolyai University) and Claudiu Toma (Universitatea deVest din Timisoara) for supplying me with books and other resources on Da-cian archaeology, as well as their helpful insight and comments. I thank Mgr.Jirí Chmelík for technical consultation.

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Abstract

This thesis defines archaeological reconstruction and describes its historyand evolution. It explores the use of computers in reconstruction and listscurrently used techniques and methods. Romanian archaeology and a briefhistorical summary of the ancient Dacian people are discussed with Roma-nian archaeologists. The practical part presents the results of attempted re-constructions of Dacian archaeological finds supplied by Romanian archaeol-ogists. Various freely available applications suitable for reconstruction weretested and their performance compared. The thesis also suggests possiblecourse of further research and development of digital reconstruction.

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Keywords

archaeological reconstruction, popular-educational illustration, 3D model-ing, automated reconstruction, virtual reality, Dacians

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Contents

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Archaeological reconstruction . . . . . . . . . . . . . . . . . . . . . 2

2.1 Definition of reconstruction and its purpose . . . . . . . . . . . 22.2 History and evolution of reconstruction . . . . . . . . . . . . . 32.3 Accuracy, quality and evaluation of reconstruction . . . . . . . 62.4 Computer use in reconstruction . . . . . . . . . . . . . . . . . . 7

2.4.1 Digital image acquisition . . . . . . . . . . . . . . . . . 82.4.2 Automated reconstruction . . . . . . . . . . . . . . . . 112.4.3 Virtual reality and interactive presentation . . . . . . . 13

3 Dacians and archaeology in Romania . . . . . . . . . . . . . . . . . 174 Practical use of reconstructive methods . . . . . . . . . . . . . . . . 20

4.1 Method overview . . . . . . . . . . . . . . . . . . . . . . . . . . 204.2 Automated 3D modeling from images . . . . . . . . . . . . . . 21

4.2.1 Testing data and software . . . . . . . . . . . . . . . . 214.2.2 Testing results . . . . . . . . . . . . . . . . . . . . . . . 224.2.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.3 Manual 3D modeling reconstruction . . . . . . . . . . . . . . . 294.3.1 Dacian knife find . . . . . . . . . . . . . . . . . . . . . . 294.3.2 Dacian knife digital drawing . . . . . . . . . . . . . . . 314.3.3 Dacian knife 3D reconstruction . . . . . . . . . . . . . . 334.3.4 Dacian arrowhead reconstruction . . . . . . . . . . . . 354.3.5 Dacian mahaira find . . . . . . . . . . . . . . . . . . . . 374.3.6 Dacian mahaira 3D reconstruction . . . . . . . . . . . . 39

4.4 Spline-based 3D modeling reconstruction . . . . . . . . . . . . 404.5 Popular-educational digital illustration . . . . . . . . . . . . . 43

5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47A Reference material . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52B Digital archive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58C Previously created reconstructions . . . . . . . . . . . . . . . . . . . 60

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Chapter 1

Introduction

This thesis deals with the topic of digital reconstruction of objects and espe-cially its use in archaeology and related fields. Its purpose is to compile upto date information about the reconstruction process as well as its evolution,history and the various approaches which are currently being used.

These approaches were tested and the test results are a part of the prac-tical portion of the thesis. As a practical example, it describes the ancientpeople of Dacia and demonstrates the possibilities of digital reconstructionusing documentation of Dacian finds generously supplied and consulted byBerzovan Alexandru (a Romanian archaeologist from Babes-Bolyai Univer-sity, Department of Ancient History and Archaeology).

The process of reconstruction is defined in chapter 2. Its relation to ex-perimental archaeology is discussed along with its development in the pasttwo centuries. Types of reconstruction and their results and purposes are de-scribed along with the possibilities computers can offer. The chapter lists pro-posals of ways to evaluate reconstruction’s accuracy and scientific or educa-tional quality.

Chapter 3 presents a brief summary of ancient Dacian history and theirrelation to other peoples living around them, their culture and overall char-acteristics. The state of Dacian archaeology, projects involving digital recon-struction and worldwide available research published in English are dis-cussed.

Chapter 4 documents the practical part of the thesis, shows the results ofvarious reconstruction methods and describes the process of achieving them.

Chapter 5 summarizes the goals I set and the overall results I achieved. Italso suggests possibilities for future research in the field of reconstruction.

Appendix A presents some of the additional reference material I used forreconstruction, Appendix B is a short documentation for the digital archiveof the thesis. Appendix C shows several reconstructions I created in the pastfor other projects.

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Chapter 2

Archaeological reconstruction

2.1 Definition of reconstruction and its purpose

Archaeological reconstruction is usually defined in relation to experimentalarchaeology.

“Experimental archaeology is a living analytical process used to re-createaspects in part or in whole, of ancient societies in order to test hypotheses orproposed interpretations and assumptions about that society.” [B1]

Reconstruction itself doesn’t necessarily offer the possibility to test hy-potheses, it is primarily done for presentation only.

A reconstruction is performed when an object, a location or an idea, whichno longer fully exist (mostly due to decay through a lengthy period of time)need to be presented to a viewer.

Alternative definition:“Reconstructions recreate buildings and other features of archaeological

sites from fragmentary remains or where they have been buried in subse-quent redevelopment. They cannot be exact reproductions of what was there,but are a picture of probability - a picture of what is in the archaeologist’s eye.Ideally the artist will use all available archaeological evidence to place recon-structed buildings in their historical context to create a peopled landscapethat provides scale and actuality” [B2]

Contemporary university education tends to focus mainly on archaeo-logical illustration, a subset of, or a process very closely related to recon-struction. Immediately useful to archaeologists, it provides the much neededsimplified and stylized documentation of objects. While an illustrator mayattempt to fill in an approximated vision of the damaged or missing partsof an object, illustration usually focuses on depicting the current state of theobject and the site it has been found in (documentation of such sites is called“surveying”) . It’s up to the illustrator to depict it as truthfully and accuratelyas possible, while keeping the drawing stylized. It is in fact an interpretationof the object, the artist processes the observed shape, form and function.

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2. ARCHAEOLOGICAL RECONSTRUCTION

Reconstruction builds on top of such descriptive representation. The goalis to recognize and acknowledge shape, form and function of the object inits current broken and decayed state. And with this in mind approximate itsshape, form and function as they were when the object was new and undam-aged.

Švácha[B7] lists these types of illustration used in archaeology:

• technical documentation for scientific publications (Meant to be readand viewed by scientists, it does not necessarily strive for much aes-thetic beauty, rather for accuracy and the ability to communicate ex-actly what the artist saw and drew.) This includes documentation offinds, the site, typological tables, samplers, analytical graphs and ta-bles, material and functional reconstructions1, schematics and humor-ous pictures.

• popular-educational illustrations (Meant for educating the non-scientists,the goal is to make archaeology and its results accessible.) Unlike inthe first case, the artist here is most often not an archaeologist, rathermerely given advice by one. A popular subject of such illustration andreconstruction is the evolution of man.

• illustration for fiction (Similar to the popular-educational reconstruc-tion, but very rarely nearly as scientific.)

Reconstruction as defined in this thesis falls in the first two categories.

2.2 History and evolution of reconstruction

Reconstruction and archaeological illustration first appeared in the 18th cen-tury in the form reflecting the general view of ancient objects, a rather anti-quarian one. Up until the late 19th century, when archaeology as a real scien-tific discipline started to emerge, documentation and reconstruction of findswas created with little sense and order, mostly as lists and samplers of vari-ous ancient objects depicted from one side only. Drawings like that, lackingproper measurements, (using individual size ratios instead) were eventuallyreplaced almost exclusively by photography in the first half of the 20th cen-tury.

1. part of experimental archaeology, the goal is to recreate the artifact as a real functionalobject

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Site documentation suffered similar problems. In the early stages the artistsfocused mostly on the artistic side rather than technical drawing. Later, to-wards the end of the 19th century the artistic focus prevailed, but it wenthand in hand with technical precision.2

With the use of photography new issues arose. A photograph captureseverything about the scene, it does not interpret it. It does get distorted, it ispossible to be taken badly, out of focus, the scene can be poorly lit etc.

Some semblance of a norm started to appear in the second half of the20th century. The number of drawings was again slowly increasing until itroughly equaled the amount of photographs.

The popular-educational reconstruction went through a similar evolutionprocess. The first attempts to illustrate human history truthfully (as opposedto the previous custom of depicting ancient past in context of contemporaryreality, like Roman soldiers and Trojans wearing medieval clothing etc.) werequickly influenced by growing nationalistic tendencies. Hardly based on sci-ence, these depictions were biased in many ways. Ancient people were ide-alized, or in another extreme, depicted as entirely primitive and beast-like.Illustrators up to this day often directly copy, or at least reference romanti-cist paintings and accept their mistakes. (Even very popular illustrators likeZdenek Burian are criticized for adhering to dramatic stereotypes not basedon research, but rather on art tradition of romanticism.) This kind of political,racial or nationalist bias is unfortunately still present in modern archaeology,as documented in the case of the Siberian Ice Maiden and her facial recon-struction controversy. 3

Švácha[B7] explains the evolution of illustration towards present day, mo-tivation of the illustrators and their various approaches to reconstructions inmuch more detail.

An important feature of the popular-educational reconstruction is thenarrative quality. Without the need for drama and deep storytelling of il-lustration for fiction, such reconstructions still have to convey meaning and

2. This artistic brilliance combined with technical precision and scientific accuracy wassuccessfully followed later on. An example of such an artist could be Alan Sorrell. http://www.alansorrell.ukartists.com/index_files/Page433.htm3. Two entirely different reconstructions were made. One by a Russian artist gave thewoman clearly Caucasian features, another by an international reconstruction team showeda more Mongoloid face. A genetic examination of the mummy suggested the woman wasnot related to the Altai people, Nenets and Selkups are her most likely descendants. Thiscaused an uproar in the local Altai community and protests were organized demanding areburial of the woman. While a burial of an Europoid looking woman in the middle of theAltai seems strange, the Pazyryk people appear to have been rather ethnically diverse. Othermummies found in the region have clearly Mongoloid features. [E5]

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context of the depicted objects and people. It is not simply drawing an ar-tifact, it is drawing how it had been used in the past, or how it had beenmade.

Two masters of this aspect of reconstructional illustration, whom I findmost inspirational and whose styles I could not help but imitate in the prac-tical part of this thesis, are Angus McBride and Victor Ambrus.

McBride illustrated many books on military history as well as issues ofLook and Learn, a British weekly educational magazine for children4. Am-brus paints illustrations for books on historical topics and was one of the pio-neers of digital reconstruction painting as a part of the British archaeologicaltelevision programme Time Team.

Comparative benefits of digital reconstruction

Traditional archaeological reconstruction deals with certain issues which arenonexistent or less severe in the digital medium. Many technical papers,such as those published by Association of Archaeological Illustrators & Sur-veyors, (For instance [B3]. Other papers like [B4] however do insist illustra-tors use computer graphics whenever possible, especially CAD software forarchitecture.) advise on the storage of illustrations and technical drawings,their preparation for print/reproduction, handling of different materials etc.These art assets are usually digitized for publication. If it’s not the author’sintent to possess a physical piece of art, working digitally achieves the samegoal in fewer steps and without the aforementioned issues.

• Size of the illustration/drawing. Archaeological drawings are oftenrather large and it is difficult to photograph them properly. Such pho-tographs need to be further processed so that they can be printed in apresentable fashion and represent the depicted objects well.

• Future impossibility/difficulty of changes and editing.

• Limited ability to produce different variations of one reconstruction.Digital tools allow for cloning of elements, separate layers of contentand reversible changes.

• Storage space. Digital files can get damaged just as paper can, but ahard drive takes up considerably less space than boxes full of draw-ings. Back up in the Cloud is also an option for digital files.

4. published by Fleetway Publications Ltd from 1962 until 1982

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2.3 Accuracy, quality and evaluation of reconstruction

Gary Lock’s definition of a model: “At a basic level of agreement, a model isa simplification of something more complex to enable understanding.” [E3]

Researchers from Carnegie Mellon University describe the process of re-construction as useful and rewarding, but not entirely scientific: “It is foundthat digital reconstruction enhances the understanding of archeological de-tails, spatial relationship, and cross-referencing with field data. ... We foundthe reconstruction work is beyond simple logical reasoning and crafting.There are many cognitive processes involved in the reconstruction, such asassumptions and analogies, which play a significant role in the reconstruc-tion. Unfortunately, those inverse physics processes are hidden as “experi-ence”, or ambient intelligence rather than explicit science.” [B8]

Daniel Tietzch-Tyler defines desirable qualities of a reconstruction artistthus [B2] :

1. Artistic competence (ideally with relevant experience)

2. A strong historical interest (general rather than too specific)

3. Knowledge of architecture and archaeology

4. Analytical Intelligence (to assess all available information)

5. Research ability and/or experience (where there is little information)

6. Excellent imagination (to recreate what simply is not there)

7. Problem-solving skills (to reconcile contradictory information and iden-tify practical solutions)

8. People skills (to mediate between professionals)

9. A willingness to compromise (the client pays, so the client has the finalsay)

Points 1 to 7 seem to agree with what we know of the process of reconstruc-tion, 8 and 9 are purely practical advice.

However, uncertainty and subjective judgment of quality should not besufficient, accuracy and reliability of reconstruction should be valued objec-tively and scientifically.

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As Niccolucci [E6] observes:“As far as we know, however, there is as yet no attempt at describing a

‘scientific’ procedure to evaluate such reliability, the term ‘scientific’ referringto, as Galileo first intended, what can be repeated with the same result (be-yond experimental errors) by any other scientist. In a wider sense, it can beaccepted as ‘scientific’ also what is based on someone’s authority, as far as itis clearly stated: it is more ‘scientific’ to state “I believe this reconstruction isvalid because I am an expert in this field” than simply presenting the modelwithout any further notice.”

And further:“...we can see that from its starting point, the data upon which the model

is built accumulate an unknown, and thus unpredictable and unquantifiable,degree of uncertainty and reliability. Therefore, without a degree of confi-dence, expressed by the reliability of the incorporated data, the final modelcannot be subject to criticism from an archaeological point of view. Moreover,a non professional user of the model may be easily induced in error by thewholeness of the model and its apparent inviolability.”

He proposes a reliability system of a reconstruction ranging from “1 -completely reliable, the state in which the evidence/remains were found” to“0 - completely unreliable, too many elements were added and changed”.

The reconstruction itself is composed of a sequence of models, each modelbeing created by one step of change from the previous model. Changes to themodels are evaluated and every change decreases reliability by its specificvalue (determined by the reliability of the single step of change expressed ina fuzzy logic).

This approach seems exact, useful and sorely needed. A complete appli-cation, or integration of such a reliability system into existing applicationswill no doubt present quite a challenge. Lack of systems like this is only apart of an overall lack of standardization, guidelines and unified pipelines indigital reconstruction.

2.4 Computer use in reconstruction

“It has been long recognized that 3D objects cannot be adequately repre-sented by single pictures or collections of pictures, which can only reproduceone viewpoint or a collection of viewpoints, or even by movies, which canreproduce only one visualization trajectory: the one which was followed bythe operator during the taking. What characterizes human inspection is theviewer’s freedom to choose at any instant his viewing distance and angle

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in space. The possibility of dynamically visualizing any view of a 3D objectupon users’ interaction offered by 3D models is the representation tool clos-est to direct inspection.” [C3]

The evolution of computer use in archaeology is examined and describedin detail by Lock in [E3], from data analysis and database maintenance to GISsystems and process simulation. For the purpose of this thesis I will focuson computer use in reconstruction only. (It is however interesting to see thetwo areas overlap, for instance in the case of what Lock calls “solid models”,objects which possess not only a surface, but features as mass and volume,a whole physical representation also. These objects with textured surfacescan thus also be used in simulation.) Lock observes that computer use inmodeling and reconstruction has been on the rise since its inception in the1980s.

Computer use in reconstruction can be roughly divided into these stagesor categories:

• image data acquisition

• data analysis and automated reconstruction

• data visualization and presentation

2.4.1 Digital image acquisition

Image acquisition refers to the process of obtaining a 3D model of reality. Ei-ther for the purpose of documentation, or as a base and reference for analysisor manual reconstruction.

3D scanning

3D scanner is a device for analysis and recording of real objects into a virtual3D space. There are many different types, but their general principle is sim-ilar. The scanner emits a laser beam, x-rays or some type of sound. Judgingfrom the time it takes for this beam to travel to a surface, it calculates distanceto this point of the scene.

Scanning follows in the steps of geodetics and manual surveying, the dif-ference is in the speed of acquiring the locations of points in space. A sur-veyor may record several points in a minute, a 3D scanner may manage asmany as a few million points in the same time. Dagmar Dreslerová et al. [E2]points out that a surveyor records important points of objects in the scene,therefore doing an interpretation of it. A scanner however records the scene

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on a regular grid of points, thus capturing everything in it the same way. (Inthis aspect scanning is akin to photography.)

The scanners available to archaeologists vary in range (and resolution),from handheld devices meant for scanning of objects to portable scannersused to record whole areas and sites. [E2] Dreslerová describes these typesin more detail, as does the 3D scanning article on Wikipedia. [E5]

It is interesting to note that the use of a 3D scanner by Dreslerová and herteam in 2008 was the first ever in Czech Republic. As such, this technology isdescribed as promising and perspective.5

Another type of scanning devices, called “optical triangulation scanners”,is often associated with 3D scanners, but in fact belongs more under pho-togrammetry. A stripe of light (laser or another bright source) is projectedonto the scanned object and a camera records it. Based on the changing de-formation of the stripe (caused by perspective and the shape of the object)the scanning software calculates the depth value of points on the surface ofthe object.

These scanners are usually used for scanning objects rather than wholeareas. As an alternative to the stripe of light, a cast shadow of a pencil can beused. [C12]

3D scanners typically produce a set of points in 3D space, a “point cloud”.These points can then be analyzed and manually edited. Dreslerová givesthe example of removing tree point clouds from a forest scene to reveal thelandscape.

For presentation the points are triangulated into a polygon surface.There are quite a few open source 3D scanning projects available on-

line [C13], its cost seems to be getting rather affordable. A wider spread ofthis technology among the archaeological community could significantly im-prove the state of 3D reconstruction and documentation worldwide.

Photogrammetry

“Photogrammetry has been defined by the American Society for Photogram-metry and Remote Sensing (ASPRS) as the art, science, and technology ofobtaining reliable information about physical objects and the environmentthrough processes of recording, measuring and interpreting photographicimages and patterns of recorded radiant electromagnetic energy and otherphenomena.” [E5]

5. I did not have the opportunity to test a 3D scanning device, nor did the Romanian ar-chaeologists I cooperated with. That is why I did not include it in the practical chapter.

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This approach involves several steps and groups of algorithms. The ob-jective is to produce a truthful 3D model of an object or a scene after process-ing a set of photographs taken from viewpoints around the object. Similar topanoramic photography, (compositing several sequential photos into a wideview) the algorithm usually involves: [C14]

• finding and using recognizable points shared by the photographs (of-ten limited to nearest neighbours to optimize the algorithm)

• a 3D map of the camera’s movement around the object in space iscalculated, each position corresponding to one photograph in the set

• auto-calibration and bundle adjustment to improve the results of pre-vious steps

• creation of an accurate depth map from combining several dense dis-parity maps

• creation of a textured 3D model using results of previous steps

Pollefeys in [C14] demonstrates the possibilities of photogrammetry by re-constructing not only complex objects, but dig sites as well. (He also suggeststheir use for augmented reality presentation.)

Manual modeling

Manual modeling refers to creation of 3D polygon models by an artist ina 3D modeling software package (3D Studio Max, Cinema 4D, Maya etc.).Recent development of digital sculpting (ZBrush, Sculptris, Mudbox) toolsalso allows reconstruction artists to create highly detailed objects in a similarway they would with clay.

Its purpose and the methods used in manual modeling will be covered indetail in chapter 4.

Ondrej Malina in [E2] finds manual modeling useful mainly for explo-ration of various reconstructive possibilities, presentation of structure andfunction of objects (through section views and animations).

While working on the manually modeled reconstructions, I created a setof non-realistic Cinema 4D materials for possible use in archaeological pub-lications. They make use of the Sketch and Toon rendering system integratedinto Cinema 4D. S&T (Sketch and Toon) offers tools for rendering in stylesmimicking traditional artistic methods as well as technical drawings andschematics.

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Figure 2.1: A test render of a landscape model using a pencil drawing S&Tmaterial.

These materials attempt to imitate drawing styles found in the practicalhandbook for archaeological illustrators. [B6] The controls and various ma-terial and renderer settings are explained in Appendix B.

2.4.2 Automated reconstruction

Automated reconstruction requires only the input data for analysis and pos-sibly a setup of parameters, the reconstruction itself is performed automati-cally. 6

Automated fragment assembly

Archaeological finds are not only found with parts missing, often they are en-tirely smashed into bits. Manual assembly of pottery shards is a difficult andtime-consuming task, an accurate automated approach is certainly needed.

Most current solutions are in fact semi-automatic, still requiring user in-put and interaction.

6. Photogrammetry could possibly be defined under Automated reconstruction as well. Iput it under acquisition, because its output may need to be processed further to become areal reconstruction, it is a way to acquire rough models.

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Melero, Torres and León describe the goal of their application:“One of the aims of this software is that the archaeologist should feel

comfortable working with it. The goal was not to build "perfect" software,leaving no freedom to the expert to interact in the reconstruction process,giving the solution without taking into account the archaeologist’s experi-ence and knowledge. Therefore, our system follows the same steps as in thetraditional procedure, but using an interactive process that works with a 3Dmodel of the sherd” [C15]

The process involves:

• recording of the fragments by using a 3D scanner

• manual interactive orientation of the fragments

• estimating the best intersection of the shard with a plane to acquire itsprofile

• manual matching of generated fragment profiles

This method’s accuracy is reported around 85%.Yifan Lu [C16] suggests a similar approach with the substitute of pho-

togrammetry for 3D scanning. He also gives an extensive overview of previ-ous literature on the subject.

Content aware editing

Content aware tools modify parts of a 2D image in such a way that the con-tents of the image are damaged or warped as little as possible. Paper byFinkelstein [E4] shows examples of such use:

• removing elements or objects from the image while keeping the back-ground intact. (This is done by approximating what would lie behindthese objects, “guessing” from their surroundings.)

• changing objects’ structure in a way that seems natural, mimickingits major features (making a building look more narrow without com-pression deformation, adding a tower etc.)

• supplying a set of constraints (leading lines of the objects, which aremajor features we wish to keep, as well as an outline/mask of a miss-ing part) the algorithm “repairs” a broken ancient monument. (Whichis exactly the kind of reconstruction I wanted to test in 4.3.2.)

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Figure 2.2: Results of a reconstruction attempt using the Content awarefill tool. photo source: http://chinesenotes.com/chinese_fonts_history.php

As implied in the last bullet point, this process may not be entirely automatedand satisfactory results may require user input.

The usefulness of these tools in archaeology is limited at the moment.It would certainly work while applied to a regular repetitive pattern withmissing pieces, in that case it is possible to “fill” these holes with correctcontent. It is not however able to “guess” specific content in irregular surfacetextures (drawings or carvings of people and real objects etc.).

2.4.3 Virtual reality and interactive presentation

“Virtual reality: The computer-generated simulation of a three-dimensionalimage or environment that can be interacted with in a seemingly real or phys-ical way by a person using special electronic equipment, such as a helmetwith a screen inside or gloves fitted with sensors.” [E1]

Virtual reality is a tool with a wide spectrum of use in archaeology. Projectshave been proposed and realized that allow the user to walk in a virtual mu-seum, look at models of finds and interact with them. Others reconstructwhole settlements or excavation sites and the user is able to walk throughthem and see the reconstructed area from first person view, or even fly throughthem.

“The concept of virtual archaeology was first proposed by Paul Reilly(1990) to refer to the use of 3D computer models of ancient buildings andartifacts. The key concept is virtual, an allusion to a model, a replica, thenotion that something can act as a surrogate or replacement for an original.Virtual reality is being used as a generic word to refer to the growing range

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of dynamic-interactive visualization.” [D1]Advantages of such an approach are as follows:

• accessibility. Users can access such systems through the internet. [B7]

• ease of update. Models or the rendering engine can be updated on theserver side.

• complete information availability. Visual reconstructions, models andscenes can be accompanied by text, voice over, or video which furtherexplain what the user interacts with.

• validation. Metadata should make it possible to validate the authen-ticity of models and reconstructions presented online. [D3]

• interactivity. The ability to move and rotate models, switch betweenrendering modes to understand their structure or history better.

Complex information presentation and interactivity may be combined to cre-ate “augmented reality”, virtual objects and user interface projected over ourown reality. [D6]

Laia Pujol in her 2004 paper speculates that mere interactive reconstruc-tions often don’t qualify as virtual reality, because they’re not immersiveenough (viewed on a mere computer screen instead of a VR cave) and be-cause the reconstruction is too dependent on artistic interpretation (it’s notsuffieciently realistic and scientific). She suggests a unified hyper realistic VRshould be used by archaeologists as their primary tool of choice. [D2]

Tools are becoming available which could possibly make such interac-tive reconstructions less difficult and laborious to produce, even to archae-ologists with limited computer knowledge. Such tools are for instance theVRML (Virtual Reality Modeling Language), or The Castle Construction Kit.

An internet protocol since 1995, VRML can be used on most major plat-forms and implemented by anyone with a word-processing package, an in-ternet browser, and the relevant plug-in. [D4]

TCCK is an interactive creation software based on the Generative ModelLanguage and OpenSG (Open Source Scene Graph system) which procedu-rally generates castle architecture based on direct control and manipulationof a graphical user interface. [C1]

Inspiration for TCCK was drawn from computer games with similar op-tions for construction of settlements (The Settlers and Stronghold ) and therewas demand for an application of this type in the “fantasy roleplaying com-munity”.

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An example of a complete solution to archaeologists’ needs may be foundin 3D Murale. It is “a set of tools for recording, reconstructing, encoding, vi-sualizing and database searching/querying that operate on buildings, build-ing parts, statues, statue parts, pottery, stratigraphy, terrain geometry andtexture and material texture. The tools are loosely linked together by a com-mon database on which they all have the facility to store and access data.”[C6]

Computer games and game engines

Computer games themselves offer an opportunity for simple interactive re-constructions. The massively multiplayer online roleplaying game Roma Vic-tor (unavailable since 2011 due to server problems) allowed players to as-sume roles in a well researched and reconstructed environment of ancientBritain under Roman rule. Both of these political factions in the game weredriven and controlled by players. The attention to detail and focus on au-thenticity made the game into a viable learning tool for history students andenthusiasts.

Many (especially independent) games come with an editing toolset thatallows for easier modification of the game. To mod a game is to create customenvironments, objects, characters, or even unique or stand-alone games on anexisting game engine.

Therefore it is only the reconstruction content that needs to be created,the rendering engine, the avatar controls and interaction framework are al-ready in place. Such games create communities focused on specific historicalperiods and areas they wish to recreate. While primarily intended for enter-tainment, these modifications have the potential to be used as educationaltools in high school and even university history classes.

Game engines may prove to be a free solution for online presentation of3D reconstructions, Unity (http://unity3d.com) for example can be in-tegrated into the browser or converted to Flash, available for mobile devicesas well.

The topic of game engine use for archaeological reconstruction throughmodding is explored in great detail by Roberto Andreoli et al. in [D5]

Case example: Europa Barbarorum

The “Europa Barbarorum” modification for Rome:Total War [A2] was givento US high school students by their teacher. As part of their Greek I coursethe students were encouraged to play the game, control one of the Hellenic

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factions and experience a simulated reality in the role of an ancient ruler.They were told to keep journals and document their achievements. DavidWebb, their teacher known mainly by his internet handle Teleklos Archelaou,reported his results on the Europa Barbarorum internal forums.7

The students were not just playing a game. They learnt about militarytactics, religious practices and even fairly complex ancient politics. All dur-ing an (as reported) enjoyable interactive process, using their own input andreactions to events.

(Examples of reconstructions I created for Europa Barbarorum 2 and ThePeloponnesian War8 are presented in the Appendices.)

7. “Just an update - my first journal submissions were today, and while some were prettyrough, some were really great starts. ...Thankfully two of the guys playing Baktria tookKophen today (one after losing his king there in an earlier auto resolve battle) - Baktria canbe really boring without it. In a Q&A with me they figured out that they should train spiesand send them out to see what they should do next. I’m just hoping the Seleukids don’t de-stroy them for a while at least. One fellow who plays as the Macedonians lost a huge battletoday at the Isthmus after he failed to keep his phalanx and mercenary hoplites in a lineand chased after some skirmishers on the flanks. Then a spartan unit ate his lunch, and sepa-rated his army in two and destroyed them. Corinth fell the next turn, but he deserved it - hehad destroyed Phidias’ statue of Zeus earlier that year and I’m telling him it’s sort of likethe people rose up against his evil rule there. One girl as Epeiros, destroyed the buildingsin Taras, raised taxes, and pulled her troops out , the Romans finally took it, but her armywas still there. She marched them south to Rhegion to destroy them attacking the city, butmet an army en route, defeated them, and is now starving out the garrison at Rhegion. ...They enjoyed it at least .”8. TPW website: http://forums.taleworlds.com/index.php/board,110.0.html

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Chapter 3

Dacians and archaeology in Romania

This chapter contains a selection of historical information relevant to the re-constructions produced in chapter 4.

Dacian history

“The Dacians were an Indo-European people, very close or part of the Thra-cians. Dacians were the ancient inhabitants of Dacia (located in the area inand around the Carpathian Mountains and east of there to the Black Sea).This area includes the present-day countries of Romania and Moldova, aswell as parts of Sarmatia (mostly in eastern Ukraine), Moesia (Eastern Serbia,Northern Bulgaria), Slovakia and Poland. They spoke the Dacian language,believed to have been closely related to Thracian, but were culturally influ-enced by the neighbouring Scythians and by the Celtic invaders of the 4thcentury BC.

It is generally proposed that a proto-Dacian or proto-Thracian people de-veloped from a mixture of indigenous peoples and Indo-Europeans from thetime of Proto-Indo-European expansion in the Early Bronze Age(3,300–3,000BCE) when the latter, around 1500 BC, conquered the indigenous peoples.The indigenous people were the Danubian farmers and the invading peopleof the BC 3rd millennium were the Kurgan warrior-herders from Ukraine-Russian steppes...by 300 BC they had formed a state, founded on a militarydemocracy and began a period of conquest.” [E5]

After the Dacian-Roman wars in the 1st and early 2nd century AD, Daciabecame a Roman province and the Dacian people were probably romanized.Wikipedia agrees with Ioana A. Olten that: “The impact of the Roman con-quest on these people is uncertain.” While the Dacian kingdom ended withRoman occupation, archaeologists and historians generally disagree on thenumbers of Dacians killed, assimilated and relocated. People in Romania be-came heavily Latinized, either by cultural conversion, or by replacement ofthe population with Roman citizens.

17

3. DACIANS AND ARCHAEOLOGY IN ROMANIA

Dacian culture

There are no surviving literary sources in the Dacian language. Very littleis known about it, only a handful of Dacian words survived to this day. Tounderstand the identity of the Dacians, we are forced to look at their neigh-bours and their accounts. Also at archaeological evidence attributed to Da-cians themselves. [A1]

“They were greatly influenced by the people with whom they came incontact: most prominent among them the Hellenes, Skythai, Halstatt-era Kel-toi, and even Persai.” [A2]

The Dacians traded with the Greeks, their metal products are said to havereached as far as Scandinavia. They are described in ancient sources as onebranch of the Thracians, yet their culture was distinctive enough, influencedby steppe tribes, Greek and Celtic culture. They accepted Greek money andstarted minting their own coins based on Greek coinage. These examples ofcultural diffusion are especially useful for artifact reconstruction, as it seemsreasonable to draw inspiration from finds attributed to these influential cul-tures.

“The bow had an important role in Getic rituals relating to Gebeleizis andthus experienced archers would always be appreciated within their commu-nity...Archery was a fairly common skill, and arrowheads feature in even thericher burials. Archery in the region reached its pinnacle around the first cen-tury AD, by which time the composite bow had been widely adopted.” [A2]

This is relevant to the arrowhead reconstruction in chapter 4.

“The society clearly stratified (from the 2nd century BC on into severalcenturies AD) into two social groups: the komatai (the free people, later the“Comati” spelling is used) and tarabostes (the nobility). The leaders of thestate were selected from the nobility, which was distinguishable by the furcaps they wore. A powerful but smaller third social class, the priests...” [A2]

This information is essential for identification of various Dacians depictedon Roman monuments. (I use it later for the popular-educational illustra-tion.) How accurate are these depictions? There seems to have been a bias,Romans preferred to portray Dacians as half naked barbarians inferior to Ro-mans. Hadrian Daicoviciu however agrees that the bias is present more in thegeneral meaning of the depictions. Their distortion and fabrication of events,rather than an inaccurate depiction of Dacian clothing. For the purpose ofthese reconstructions, Trajan’s column is a relevant source.

[A2], [A3]and [A1] go into much more detail on the wars of Dacia againstRome and their impact on late Dacian culture.

18

3. DACIANS AND ARCHAEOLOGY IN ROMANIA

State of Romanian archaeology and digital reconstruction

Claudiu Toma comments:“Unfortunately Romanian archaeology is not promoted enough. Almost

everything we know about the Dacians is from archaeological excavations,Trajan’s Column and few ancient sources such as Strabo, Herodotus etc.

3D projects are not widespread in Romanian archeology. There are somereconstructions being made by passionate people. One project was organizedby a university (...) From what I know there is another project called: Proiec-tul romania digitala 3D - 3D Digital Romania project, but it focuses on roadmaps with tourist information. It is a private initiative.”

Toma is refering to T.O.M.I.S., a 3D interactive virtual reality project startedin 2012.1

Ioana A. Oltean describes her involvement in Romania’s first aerial re-search programme:

“This study would not have been possible in Romania only a few yearsago, before the first aerial reconnaissance programme exclusively for archae-ological purposes was started by Prof. W. S. Hanson and myself in WesternTransylvania (1998–2004). Apart from providing the vital photographs andmaps, the project introduced a new perspective to archaeology in the regionwhich has been promoted throughout the present volume.” [A3]

Literature on Dacians

There does not seem to be a great wealth of Dacian research published inEnglish. Alexandru supplied me with articles and books by Valeriu Sîrbuand Horatiu Crisan. There are also publications by Sîrbu available in French.Ion Grumeza’s book “Dacia - Land of Transylvania, Cornerstone of AncientEastern Europe” is considered to be “plagued by unfortunate nationalist un-dertones”.

Of most help to me was a book by Hadrian Daicoviciu, translated intoCzech under the title “Dákové”. [A1] It is a popular-educational publication,but Alexandru judges it to be rather valuable to a layman.

1. website:http://cerva.ro/tomis/

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Chapter 4

Practical use of reconstructive methods

4.1 Method overview

Beside giving a description of the theory of reconstruction and an overviewof its current computer-aided methods, this thesis is supposed to demon-strate my ability to effectively use these methods to create usable reconstruc-tions of real archaeological finds from Romania.

I chose to produce them by the means of:

• four free applications for automated 3D modeling from images

• manual 3D modeling of three artifacts in Cinema 4D

• manual 3D modeling of vessels based on spline section outlines, com-paring a specialized application QP and the general Cinema 4D pack-age

• digital painting in the popular-educational style

Photogrammetry or automated 3D modeling is a very promising field fromwhich archaeologists might benefit greatly. Acquiring accurate 3D models orenvironments using only an ordinary camera and a computer has potentialto make site and find documentation much easier than it is at present. Myattempt to use these applications ended in failure, but new pieces of soft-ware are continuously being developed, which on the other hand show greatresults and promise.

Manual modeling is the current method of choice for many reconstruc-tion artists. It is laborious, but the resulting models are interpretations of thereal objects rather than exact copies. In this respect the approach is of thesame importance and use as artifact drawing and reconstruction are. The of-ten simplified model presents how the artist perceives the object, what its usewas and accentuates its important features. Unlike a 3D scan, which recordsonly the present state of the object including all damage and mesh noise. As

20

4. PRACTICAL USE OF RECONSTRUCTIVE METHODS

I decided the final products were to be rendered images (and not low poly-gon count models used in an interactive application), the models themselveswere allowed to become more detailed (composed of more polygons than isnecessary to show the basic shapes). I also used the HyperNURBS smoothingsubdivision tool in Cinema 4D to improve the models’ appearance.

Vessels require (and are suited for) a different approach to manual model-ing. Their (mostly) symmetrical design allows for the use of spline modelingmethods. While it seems possible to automate this process, vessel section cutdiagrams are still often drawn by hand of the artist. It is convenient to usethose as reference for manual creation of 3D models. I compare the perfor-mance, ease of use and resulting models by QP and Cinema 4D.

I discussed the importance and use of popular-educational style paint-ings in previous chapters. An illustration of this kind requires accumulationof extensive reference material, artistic skill and the also previously discussed“imagination”. I demonstrate both the advantages and shortcomings of thisapproach.

4.2 Automated 3D modeling from images

4.2.1 Testing data and software

I chose to test four applications all of which were either free, or at least of-fered a free trial functionality. Arc3D and 123D Catch use clients to uploadthe photo sets online and apply their algorithm on their side, then send backthe results. PhotoSculpt Textures is the simplest of the four, using only twoimages to create a stereo view. Insight3D requires manual user input, but alsooffers the most customization and options.

The tested data were four sets of sequentially taken photographs (eachset composed of around 50 photographs). They form roughly 360 degreesaround the objects and in some cases above them as well. The objects pho-tographed include:

• a slightly reflective ceramic bowl photographed on semi-glossy table

• a rather reflective and glossy porcelain shard photographed on a matteboard

• a matte brick-like roof tile on a matte board

• a matte camera case on a matte board

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Figure 4.1: Example of 3 sequential photographs

4.2.2 Testing results

Arc3D

ARC 3D was and is being used successfully to reconstruct archaeologicalfinds, the example pictures are displayed on the ARC 3D website. Most ofthem are highly textured and detailed sculptures and buildings and thiscould be a decisive factor for success. As the ARC 3D website says:

“Not all surfaces can be reconstructed with ARC3D. In particular, thesurfaces have to be textured and non specular. This means that the surfaceshould have irregular intensity changes and not be too reflective. For in-stance, A completely white plate, glass buildings, shiny cars and chromedmachine parts are difficult or impossible to reconstruct. Brick, stone andother textured items are easier.“ [C2]

Judging from my results, ARC 3D does not perform well in the recon-struction of small objects photographed in the specific way I did. The result-ing models were far from usable despite the fact I stayed as close to photog-raphy recommendations of the authors as possible.

The tutorial text suggests ARC 3D does not handle glossy and reflectiveobjects well, (Reflections and specular spots make pixel matching difficult.)this may be one of the reasons my experiments failed. On the other hand,two of the photographed objects had matte surfaces and failure in their caseshouldn’t be attributed to glossiness. It is possible the photos themselvesweren’t of sufficient quality, sharpness, or perhaps the EXIF (Exchangeableimage file format is a standard of meta data that specifies the formats forimages.) of the cameras used wasn’t compatible with ARC 3D.

An example of my attempted and failed reconstruction is a terracotta rooftile photographed on a piece of chipboard. 48 photos taken in roughly regu-lar angle increments to make full 360 degrees were processed by the Arc3Dclient and uploaded to their server to be run through the Arc3D analysisand reconstruction algorithms. The other test subjects were not reconstructed

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Figure 4.2: A successful reconstruction of a relief by Arc3D (source: Arc3D)

any better, no matter their texture or the surface on which they were pho-tographed.

Insight3D

Insight3D is primarily developed for reconstruction of buildings, statues andother man made landscape features. It also seems to favor detailed and roughlytextured objects, flat and glossy surfaces not so much. [C5]

After choosing to use as large version of the photos as possible and neigh-bor only matching method, Insight3D was able to find at least some match-ing key points. The point cloud however was too small to form a usable 3Dsurface which I could triangulate. The manual part of the reconstruction pro-cess, where the user is required to mark major straight lines in the form ofthe reconstructed object, also proved to be difficult if not impossible to usefor round or irregularly shaped objects (such as the soft camera case). That isunderstandable as the software is focused on reconstructions of architecture.

The results were similarly poor for all test objects, all test photo sets pro-duced an insufficient amount of key matched points and their point cloudscould not be triangulated into usable 3D surfaces.

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Figure 4.3: Sample from the roof tile photo set

PhotoSculpt Textures

PhotoSculpt Textures has similar limitations as the previous two:“Can’t work on shiny or reflective subjects like cars. Can’t work on very

complex depth structures likes tree branches. Can’t work well on flat areasof objects with no detail, like modern buildings. Doesn’t work well on bigrepetitive patterns.” [C4]

Its input set of two stereo photos also severely limits the possibilities ofthe output. The result however is the least deformed of the first three and thereconstructed object is remotely recognizable, if ultimately unusable. Recon-structed models were similar for all test objects, glossiness of test surfacesdid not seem to have a significant impact.

Autodesk 123D Catch

This is a service similar to Arc3D. [C8] After downloading the client, the userselects the photo set and uploads it to the service provider. It is processed byAutodesk’s algorithm and sent back to the application as a 3D scene showingthe reconstructed models and camera positions for all the photographs in theset, which it managed to identify.

I had to downsize my photos, because the client repeatedly failed to up-

24


Figure 4.4: A terracotta roof tile reconstruction by Arc3D

Figure 4.5: A successful 3D reconstruction sample by Insight3D (source: In-sight3D)

25


Figure 4.6: A set of camera case photos analyzed by Insight3D

load them all. Testing of this application also convinced me that the photosets I used were somehow invalid, or unusable for this process in general.One of the four sets was marked as entirely faulty and the algorithm did notrecognize any camera positions at all. The other three sets each had a certainamount of unused photos, ranging from a few to more than a half.

In spite of that, 123D Catch produced by far the single best result, a modelwhich actually resembled the object and its shape. It could be selected, sep-arated from the reconstructed background and exported for further process-ing, (smoothing out and filling of polygon holes) it would not be howeverof much use as a reconstruction. The resulting model was too crude and un-shapely.

4.2.3 Conclusion

My failure to produce a usable 3D reconstruction of an object photographedby a common camera has to be attributed to faulty testing data. It may beinsufficient focus and sharpness, or perhaps an unsupported format of meta-data, ill suited chaining of camera positions, or something entirely different.

The technique of automated 3d acquisition from a set of photographs has

26


Figure 4.7: A 3D reconstruction of a porcelain shard by PhotoSculpt Textures

been shown to be effective and demonstrated to work rather well in archae-ological context.

An example of a very promising project is ProFORMA (Probabilistic Feature-based On-line Rapid Model Acquisition). [C9]“ProFORMA uses a fixed videocamera to allow on-line reconstruction of objects held in a user’s hand. Par-tial models are generated very quickly and displayed instantly, allowing theuser to plan how to manipulate the object’s pose in order to generate addi-tional views for reconstruction.”

The model generated in a few seconds while the object is rotated in theuser’s hand is simplified, yet well captured and segmented.1

A proof this type of reconstruction is entirely possible to do using freelyaccessible open source tools only is given in [C11].

1. A video demonstrating the process as well as the paper itself can be found here: http://mi.eng.cam.ac.uk/~qp202/

27


Figure 4.8: A 3D reconstruction of a bowl by 123D Catch

28


4.3 Manual 3D modeling reconstruction

Manual modeling can be seen as the computer equivalent of a reconstruc-tion artist drawing the object in its original state. As mentioned previously,simplifying is desirable and it is important to recognize and emphasize sig-nificant features of the object. Its construction and purpose should be madeobvious and clear.

For manual modeling I used Maxon Cinema 4D2. Manual 3D reconstruc-tion of finds such as pottery, small weapons or tools requires rather basicmodeling and texturing skills. I mainly followed a modeling, UV editing andtexturing tutorial by Pavel Zoch. [C7]

The artifacts reconstructed this way were a knife, an arrow and a shortsickle sword.

4.3.1 Dacian knife find

This Dacian knife is described by B. Alexandru thus:“This one is a knife, as you can see, of rather small size. On it, there is

incised a mark, which can represent either a mark of property, or a markof the workshop. Similar knives like this one can be found also in Central-European Celtic World, over a long period of time (from about 3rd centuryBC to 1st century AD)”

The object is roughly 20 cm long and at most around 3 cm wide, theblade is broken off 8 cm from the handle. According to Alexandru, the han-dle would have most likely been wrapped by a strip of leather. I thought thisidea to be very plausible, as the hilt of the knife ends with the iron wire form-ing a loop. While ring hilted swords and knives are not a rarity for instancein the steppe cultures throughout antiquity and early medieval period3, inthis particular case it appears to be more of a practical element (for tying aknot on the leather strip wrapping the handle).

Alexandru supplied me with a drawing of his, which clearly shows theblade marks, otherwise hard to make out from the photographs. (As dis-cussed in previous chapters, photographs capture everything about an ob-ject’s current state, but do not help in identifying important features likethese marks.)

It depicts the blade’s profile, which is also absent from the photographicmaterial.

2. product website: http://www.maxon.net/3. Examples of ancient ring hilted swords in appendix A.

29


Figure 4.9: Dacian knife drawing by Berzovan Alexandru

30


Figure 4.10: Dacian knife 2D reconstruction comparison

The original photos of both sides of the knife are available for viewing inthe Appendices.

4.3.2 Dacian knife digital drawing

Before attempting to reconstruct the knife myself, I wanted to try an auto-mated approach.

One of the recently popularized tools which I thought might be usefulwas the Content Aware Fill developed and implemented by Adobe in theirPhotoshop CS (5 and 6) software. Behind this tool is the algorithm developedby team of researchers from Princeton University, Adobe and University ofWashington. [E4]

Their improvements to the algorithm working speed made it possible forit to be used as realtime editing tool.

The comparison figure 4.10 shows the original photograph of the object(1.), an automated reconstruction produced by the content aware fill tool (2.)and a reconstruction created manually using the healing brush tool.

As suggested previously, imagination only is not sufficient for a seriousreconstruction. The algorithm produces a knife like object, as does imagina-

31


Figure 4.11: The second knife drawing and reference comparison (Objects arenot to scale.)

tion. The algorithm works only with the image data and its pre-programmedheuristics, imagination works with image data and an intuitive knowledge,all the stored information about knives in a mind of the artist. The manu-ally painted knife looks more plausible, because it mimics shapes of existingknives.

H. Švácha, quoting Libor Balák, points out the necessity of a well ref-erenced multi-field scientific approach. [B7] By careful drawing of projectinglines matching the original object’s contours and referencing related Pannon-ian4, Celtic and Germanic knife finds of the same period I came to a verydifferent shape.

I straightened the handle, believing it to be bent in the photograph (ac-counting for damage from being buried). As observed in many related refer-ence knives and while judging the practical mechanics of the tool, a handlealmost exclusively bends towards the edge, not away from it.

The blade is longer and more slender, slowly tapering towards a narrow

4. Pannonia was a Roman province located roughly over the territory of western Hun-gary, eastern Austria, northern Croatia, north-western Serbia, Slovenia, western Slovakiaand northern Bosnia and Herzegovina. Its inhabitants were Indo-European Pannonii relatedto Illyrians, later also by various Celtic tribes. This combination of a fairly close proximity toDacia and the nature of Pannonian population makes it a good analogous to Dacia, just asThracia was. [E5]

32


Figure 4.12: Example of the Twist deformer beign applied

point.I used this drawing as base for the manual 3D reconstruction.

4.3.3 Dacian knife 3D reconstruction

I began by creating the handle of the knife. I considered using a displacementmap5, but I soon realized a model would end up looking better.

The handle started as a cube, which I edited into a prism. I then used theTwist deformer to twist the handle into the desired coil shape. I made thisobject editable (converted it to the polygon mode) and formed the curvedring pommel by using the Extrude tool.

I continued using Extrude on the other end of the handle, moving thenewly created points of the blade to line up with the reference blade’s shape.Especially challenging was the tip of the blade, where many of the blade’slines were converging in a small area. I had to improve its meshflow quite alot. In hindsight, it might have been wiser to use the Create Polygon tool andSymmetry instead of Extrude for the blade.

Then I focused on the blade’s distal taper and its profile. The knife has asingle edge, so I used the Move tool to make it thinner on the curving sideand form an edge. The blade also gets thinner in the direction from the hilt

5. Displacement mapping includes the term mapping which refers to a texture map beingused to modulate the displacement strength. The displacement direction is usually the localsurface normal. [E5]

33


Figure 4.13: Modeling the cord tied to the ring pommel

towards the tip of the blade.I moved to modeling the handle’s wrapping. The base was another cube

turned into a prism. I then used the move tool with the Soft Selection optionto create the illusion of a soft material wrapped around the twisted metal ofthe handle. Since I wanted to portray the handle as being wrapped in leathercord, I used Extrude again and modeled an end of the cord tied to the ring ofthe pommel.

That took the model to finish. I put it into HyperNURBS so that it ap-peared smoother.

I then unwrapped the UV coordinates and started texturing. The materi-als used are based on Cinema 4D presets for “organic metal” and “leather”.I changed the materials’ settings to better fit the reconstructed object.

I switched the layout of Cinema 4D to UV painting style and painted intothe texture of the knife. Making the blade’s edge scratched from sharpeningand giving grain to the blade. I also painted into the bump channel of thematerial and put in the unexplained blade marks.

The handle wrap is textured with a procedural material depicting thewrapped leather cord, this is achieved by displacement mapping. A poly-gon selection is used to make the strap tied to the pommel seem to be made

34


Figure 4.14: Final renders of the knife

of the same leather material, yet non-striped. (It would have been distortedand striped if left with the same material as the rest of the handle wrap.)

Only after modeling the way the leather strip is tied to the handle’s loopending I discovered a nearly identical reconstruction of a similar knife typeonline. This Celtic knife replica’s photo is presented in Appendix A. (Its sim-ilarity does not make my reconstruction infallibly correct. It merely suggestssuch a conjecture on the way the wrapping is tied and attached is a reason-able one.)

The model itself is rather high in polygon count (with the HyperNURBSobject on top of that) and for the final render I used procedural materials. IfI were to use the model in a game engine, or some other kind of interactivereconstructive presentation, it would be advisable to reduce the number ofpolygons (There are quite a few free polycount optimizing applications avail-able.) and “bake” the materials into diffuse, specular and bump bitmaps.

4.3.4 Dacian arrowhead reconstruction

B. Alexandru calls this iron object “a typical Dacian arrowhead”. It is roughly8 cm long and about 1,5 cm wide. It is corroded, but overall in a rather goodcondition. Since there seem to be no pieces of it missing, I did not need to doa preliminary drawing to reconstruct its shape before modeling.

The modeling process was similar to making of the knife. In the Top viewI laid out a rough shape of the arrowhead using the Create Polygon tool.

35


Figure 4.15: The 3D reconstruction compared to the arrowhead find

I subdivided it while set to Quads (quadrangle polygons). I then adjustedindividual points of the flat polygon so that it matched the outline of thearrow properly and also in order to improve meshflow.

I selected the inside points and pulled them upwards with the Move toolto give the arrow depth. These raised points created a ridge along the arrow’saxis.

I made sure the bottom points were all on the same zero level and then Iused the Symmetry tool to mirror the other half of the arrowhead.

I then converted the result into an editable polygon object and appliedHyperNURBS to subdivide and smooth the model.

I decided to attempt a reconstruction of the whole arrow. It is impossi-ble to judge how long the shaft of the arrow was from measurements of thearrowhead. To my knowledge there are no finds of Dacian wooden arrowparts, so in this case I had to rely on material from a related culture. Dacianswere known to use short composite bows similar to those of the Scythians,a steppe people whom Dacians lived in close proximity to. For that reasonI chose to use a Scythian-like arrow length. The closest to Scythian arrowfinds I know of are actual wooden arrows found in Saka6 burials at Urumqiin Xinjiang. These arrows measure around 80 cm, which is consistent withiconographic evidence. Arrows in reliefs and paintings are depicted as be-ing roughly two thirds the length of a gorytos or the bow. 7 Scythian bowsare about 120 cm long, which seems to confirm the correctness of the bow toarrow ratio. [B9] I used an arrow shaft 80 cm long.

6. eastern relatives of Scythians7. a scythian arrow quiver/bow holster

36


Figure 4.16: Arrow reconstruction and “pencil drawing” render of the arrow-head

I “unwrapped” the arrowhead model and fixed the UV coordinates sothat the UV mapping produced a better looking textured model. While tex-turing the arrow I re-used several materials from the knife reconstruction,with only slightly adjusted parameters. The arrowhead is iron, arrow shaftis wooden, they are tied together by a leather strap and I created a simpletranslucent material for the feather fletching.

Thanks to its almost symmetrical form, modeling of this artifact was sig-nificantly easier and meshflow of the model is better (also potentially bettersuited for use in a game engine).

4.3.5 Dacian mahaira find

Berzovan Alexandru describes this artifact: “This is one among the curvedweapons used by the Dacians, a mahaira. It has been discovered at Neudorf,a village at the foothils of the Zarand Mountains. There is a nice Dacian set-tlement there, with plenty of material discovered over the last few years.”

The object photograph unfortunately lacks a measuring ruler, so I canonly guess its dimensions. From its proportions and using the knowledge ofsimilar sword finds, my estimate would be around 40 cm of length and 3 to4 cm in the widest part of the blade.

(Figure B.1 in the appendices shows the artifacts I used as reference.)

As with the knife I first tried to reconstruct the shape of the damagedblade using the Content Aware Fill tool in Adobe Photoshop CS6 beta. Theresult is surprisingly good, probably due to the nature of the corrosion eatinginto the blade in notches, leaving parts of the blade’s original width intact. Itresembles the reconstructed blade shape I created later rather well.

Unlike any of the previous objects, the mahaira is composed of multiple

37


Figure 4.17: Comparison of the original artifact and its reconstruction by theContent Aware tool

metal pieces:

• The blade extends into a tang8 and at the end of it there is a handlebutt attached by a rivet. There seem to be three faintly visible holesin the handle. This is another point where more photographs of betterquality, close ups or a 3D scan would be of great use, I have to rely onmy own judgment and similar construction of other Dacian and Thra-cian sica and mahaira finds (which do have rivet holes in the handle).Metal rivets or wooden pegs would fit through these holes and hold awooden handle in place.

• Held by the handle butt is an oval ring.It does not seem to be a fixedring pommel as is the case with Sarmatian swords, rather it is a loosering almost resembling modern a buckle. It is possible this ring wasused for attachment of a leather belt tied to the of the user (either thearm or perhaps a waist belt). There is not any iconographic evidencefor a use of a safety system like this by the Dacians as far as I know,but similar techniques keeping the warrior from being disarmed havebeen used here and there throughout history. Another possibility maybe an attachment point for some kind of organic decoration, (tassels,feathers etc.) but this is not based on any iconography or written evi-dence either.

• A tube-like metal fitting of the handle seems to be still present wherethe blade becomes the tang. I estimated its diameter by looking at sim-ilar fitting pieces from other sica finds.

8. a narrower part forming the core base of the handle

38


These parts of the object had to be modeled separately. For reference of howthe sword is constructed and put together I looked at closely related ancientweapons, but also at quite recent originals from an entirely unrelated regionand culture. Thai and Burmese sickle swords from the 18th century seem tobe an example of a nearly identical design arising hundreds of years later ina separate region, almost certainly without any Dacian influence. A referencephoto of such weapons is presented in Appendix A.

4.3.6 Dacian mahaira 3D reconstruction

First I modeled the blade. I followed a similar approach as with the arrow-head, using the Create Polygon tool to shape a basic outline of the artifact. Ithen segmented it into convenient quadrangle polygons and moved individ-ual points around to follow the silhouette more closely.

I then selected specific edges and raised them, in order to create a profilefor the blade and the tang. I then extruded from the outline edges down-wards so that there were polygons created on the sides. The Symmetry toolthen filled in a mirrored other half.

Applying HyperNURBS to this model made its geometry quite differentand also created holes, so I opted for smoothing in the form of the Subdividetool (I did use the HyperNURBS mode of subdivision though, to keep theresult in line with the other models). That made the model less blocky andretained the general geometry much better.

The hilt fittings were mostly modeled with the Extrude tool and cylinderand cube primitives turned into polygon objects and shaped into the desiredform by using Soft Selection and the Move tool.

Similarly to the knife reconstruction, I first used procedural materialsbased on Cinema 4D presets to texture the mahaira. Then I adjusted the UVcoordinates by re-unwrapping them. I painted in details like blade scratches,grain and sharpening grind using the 3D painting interface.

As with the other models, the mahaira is also quite high in polygon count.Meshflow of the blade is reasonably good, but trying to use HyperNURBSrevealed a lack of definition in the area where the blade becomes the tang(holes appeared). The subdivision smoothing did not fix this issue, but theproblematic area ended up looking much better.

The use of overlapping meshes for the various parts of the sword wouldbe wasteful for use in a game engine. This approach is useful for the purposeof creating rendered images, it is possible to show how exactly the hilt is con-structed by stripping away these parts, or making some of them transparentetc.

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Figure 4.18: Final render of the mahaira

4.4 Spline-based 3D modeling reconstruction

Vessels and other hollow symmetrical objects lends themselves well to 3Dmodeling with splines. The spline forms an outline of the object’s sectionprofile which is then rotated around the axis to form the vessel itself.

The principle of this process is explained in figure 4.19.Sections of vessels are obtained either automatically by analytical algo-

rithms from 3D scans of pottery shards, or from on-site artists who documentthe finds and draw their interpretation of the vessel’s shape. The latter wasmy case, I chose two such drawings of Dacian vessels [B10]. One was a socalled “fruit bowl” and the other is a simple jug. I chose the first because ofits unusual long stem and the second because it is not entirely symmetricaland has a handle.

My goal was to create reconstructions of both and compare the perfor-mance in two applications:

• Cinema 4D - it supports spline modeling very well and I could haveused all the other modeling techniques directly.

• QP - [C10] an application developed by Anestis Koutsoudis.QP is lim-ited to spline modeling of vessels, it is highly specialized. This aspect

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Figure 4.19: Spline modeling: A.) Obtain profile section from a pottery shardB.) Draw a spline to follow the section C.) Use tool to rotate it around the axisD.) Final polygon mesh of a symmetrical vessel

makes it (supposedly) easier to learn and use by archaeologists.

Modeling in QP

There are not many options, but that makes the process quite straightfor-ward. I selected “body” as the part I wanted to model and I traced the ref-erence image (which i loaded into the application) with dots representingpoints of the spline. After creating the spline along those points, generatinga point cloud by rotation of that spline and triangulating it, I discovered thefirst problem.

I was not able to figure out how to make a spline closed. The usual meth-ods like clicking the last point on the first point did not seem to work. QPcurrently does not have any documentation, which is no doubt a temporaryissue of a work in progress, but it is an issue which should definitely be ad-dressed. The result of this was an open hole in the mesh right where thespline was not closed.

As I have seen Koutsoudis create a perfectly closed spline and resultingmodel in his promotional video, it should be possible to do it, if the userknows the application well enough.

QP is potentially very well equipped for modeling of the jug, as it hasthe option to generate one or more handles on the vessel. Quite like before, Idrew a spline for the body of the jug and continued to draw another splinefor the handle. At this point I ran into the second issue with QP, the body

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Figure 4.20: QP modeling results in Cinema 4D and Blender

was being generated , but the handle (despite having a spline drawn for it)would not appear.

QP only allows for exporting of the models into a format compatible withVRML. I did this for both the vessels. Then I tried loading these models inBlender (which is also compatible with this format) and after converting toOBJ also into Cinema4D.

The results were a complete mess of points and polygons. Either the ex-port function does not work properly, or it cannot cope with open hollowmeshes.

Modeling in Cinema 4D

I loaded the reference images into the background plane and traced the sec-tions with spline objects. Generating the “fruit bowl” was then a matter ofputting the spline into a Lathe NURBS object and setting a few parameters.When I got a mesh of desired complexity, I converted the Lathe NURBS intoa polygon object.

Modeling the jug followed the same steps, only the handle had to bemade on top of that. The jug is slightly asymmetrical, which was achievedby Soft Selection and the Move tool. The most difficult was the handle part, Iused the Extrude tool to pull it out of a polygon selection near the top rim. Ishaped the handle to follow the reference and attached it to the bottom pointusing the Bridge tool.

As the handle was quite blocky, I put the whole jug into a HyperNURBSobject to smooth it out.

I rendered both the vessels using a slightly modified Cinema 4D proce-dural clay preset material.

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Figure 4.21: Vessels created in Cinema 4D

In conclusion, modeling vessels in Cinema 4D is a simple task, but theartist is forced to learn to control a complicated application with many ad-ditional options and functions. QP would be quite perfect for archaeologistsand artists not used to working in 3D applications, but at the moment it lacksproper documentation and is very much a work in progress. (I experiencedseveral crashes of the application as well as quite a few error messages.)

4.5 Popular-educational digital illustration

The most obvious choice for a popular illustration of the Dacians would be afalx9 bearing warrior.

While I could not escape the issue of viewing the Dacians through Romaneyes (as Roman depictions are among the best evidence we have of Dacianclothing and overall appearance), I attempted to at least pick a less widelyknown and recognized Dacian theme.

I previously emphasized the narrative role of an archaeological illustra-tion, for this reason I chose to depict a complete opposite of a violent battlescene. It is a panel on Trajan’s column which depicts a procession of Dacian

9. Falx is a sickle-shaped sword or a polearm similar to the sica/mahaira, but usually usedwith both hands. The Dacians are famous for wielding the falx with great ferocity. [E5]

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Comati, children riding on their fathers’ shoulders and mothers carrying in-fants (some even on their heads).

I began by gathering reference images. Most of them come from Trajan’scolumn, although some are photographs of equipment finds. Among thosewould be the father’s knife, mahaira and fibula10. (These are the same arti-facts reconstructed in previous sections, sent to me by Berzovan Alexandru.)

The clothing’s cut and overall appearance is consistent with the Trajan’scolumn depictions and with later marble statues of Comati men (mostly lo-cated in Vatican). For the father I chose a long tunic with a slit on the rightside, a pleated cloak pinned by a fibula and decorated by tassels. He wearstight trousers and leather shoes based on folk shoe style remaining in Ro-mania to this day. As observed on the column, the boy’s clothing follows asimilar style.

The mother wears a long pleated dress tight and closed around the neck,with a pleated cloak or a shawl wrapped around her body. Her hairstyle isalso based on the column, as is the scarf she wears on her head.

For the painting itself I used ArtRage11, an art application focused onmimicking the look of traditional techniques, and a graphical tablet12.

I established the composition of the scene by roughly sketching the fig-ures using the Pencil tool. I then started adding detail, paying attention tobody language, (An illustration like this should capture a moment of life, thecharacters should not simply stand in place and pose awkwardly, showingoff their costume.) clothing reference and overall balance of the image.

When I was done with rendering in digital pencil, I created a new layerand started painting in colour using the Watercolor tool.

Everything drawn in pencil is reasonably well sourced and referenced.By adding colour I also added speculation. Color of the clothes is based onthe fact that green and ochre were not too expensive and difficult to produce.The brick red cloak of the mother is painted to look slightly expensive andluxurious. The Comati were common, but not necessarily poor people. Theman’s fibula is iron, but his wife wears gold jewelry, possibly of Greek origin.

The clothing decorative patterns are entirely my invention. Despite beingbased on Romanian folk dress decoration and patterns known from Dacia’sneighbouring and influential cultures, they are a very bold guess.

We know from Herodotus that Dacians tattooed their skin, mostly noble-

10. cloak pin11. website: http://artrage.com/12. The current generation of graphical tablets is certainly not as expensive and difficult toget a hold of as Wilcock’s “light pens” [B5] of 1982.

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Figure 4.22: Comparison of the “pencil” and “watercolor” stages of the illus-tration

men as a sign of their status and women for decoration. 13

The advantage of a digital approach to illustration is the ability to work inlayers. If I ever feel the need to change the colors or the patterns of the clothes,I can erase from the color layer and repaint the appropriate parts. If I thoughtthe illustration needed it, I could have added tattoos to the characters on aseparate layer.

The style I chose leaves room for imagination to fill in details, but moreimportantly it is not overly time consuming. The artist does not need to focuson rendering entirely realistically, instead his goal is to capture a believableand easily readable scene. To hint at little stories and complex characters,while also showing off aspects of the reconstruction it is supposed to show.

13. (Herodotus V, 6) "It was in special favour with the women, and the more nobly bornthey were, the richer and brighter coloured were the designs they used. Agathyrsi paintedboth their faces and their limbs with indelible designs (distinctive tribal marks), while thenobles also dyed their hair blue."

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Figure 4.23: Final illustration of the Comati family46

Chapter 5

Conclusion

Reconstruction theory

This thesis compiles basic information on state-of-the-art techniques and meth-ods used in archaeological reconstruction, shortly summarizes its history,main issues and the role of computers in it.

Hopefully it offers a solid base of knowledge and on top of it sufficientreferences for further study and exploration in various directions and topics.

Practical reconstruction

The goal in this part of the thesis was to see if I could produce presentableand accurate reconstructions based on photographic and literary materialsupplied by Romanian archaeologists over the internet. I also set out to testfreely available applications and explore their potential use for archaeologi-cal reconstruction.

1. The photogrammetry tests mostly ended up in failure. Not a success-ful reconstruction attempt, a valid test nonetheless. The results sug-gest a certain sensitivity of these methods to the quality (whateverattributes that involves) of the input photo set. Further experimen-tal testing into what attributes make photographs unusable for pho-togrammetry might be valuable.

2. The manual modeling of artifacts succeeded in what I set out to do -I created reasonably accurate reconstructions and produced renderedimages of them. The results were approved by Berzovan Alexandru.Admittedly, my reconstructions would have been better if I had accessto highly detailed 3D scans of the artifacts. The photographs supplieddefinitely were of varying quality, quantity of views, resolution anddescriptive standard (some even lacked a measure).

3. The spline modeling of vessels was successful as well, at least in Cin-ema 4D. QP proved to be ultimately unusable, which is unfortunate

47

5. CONCLUSION

since its design is intriguing and promising. The results were approvedby Berzovan Alexandru and Claudiu Toma.

4. The popular-educational illustration was painted in several stages. Assuggested in the chapter on reconstruction reliability, these stages areincreasingly inaccurate. I admit to painting details based on conjec-ture, but keeping in mind the purpose of this type of illustration, Ifind the result acceptable.

Possible future research

There is much to be done about standardization in archaeological reconstruc-tion. The VRML standard seems to be quite widely used, but there are notmany proposed standards for the process of digital reconstruction itself.

The field of digital reconstruction is also rather new. Research and workput into promoting it among archaeologists, as well as developing tools tomake it easily accessible, would no doubt be beneficial.

As quite essential (yet often overlooked) I view the issue of reliability andvaluation, more research following [E6] should be done and implementedinto standardized tools.

48

Bibliography

[A1] Hadrian Daicoviciu. Dákové. Mladá fronta, 1973.

[A2] Paullus. The History of the Getai. http://www.twcenter.net/forums/showthread.php?t=343507, 2010.

[A3] Ioana A. Oltean. Dacia: Landscape, colonisation and romanisation.Routledge, 2007.

[B1] Grahame Johnston. What is Experimental Archaeology? http://www.archaeologyexpert.co.uk, 2010.

[B2] Daniel Tietzch-Tyler. Archaeological Reconstruction. http://www.dantt.net/, 2007.

[B3] A.S.Maney. The Preparation of Archaeological Illustrations for Repro-duction. Association of Archaeological Illustrators & Surveyors, 1980.

[B4] Chris Philo, Andy Swan. Preparation of Artwork for Publication. As-sociation of Archaeological Illustrators & Surveyors, 1992.

[B5] J.D.Wilcock. Computers in Archaeological Illustration. Association ofArchaeological Illustrators & Surveyors, 1982.

[B6] Mélanie Steiner. Approaches to Archaeological Illustration: A Hand-book. Council for British Archaeology, 2005.

[B7] Hynek Švácha. Ilustrace V Archeologii. Zápdoceská univerzita v Plzni,2004.

[B8] Sandra Olsen, Ashley Brickman, Yang Cai. Discovery by Reconstruc-tion: Exploring Digital Archeology. Carnegie Mellon University, 2001.

[B9] Stephen Selby. Scythian-Style Bows Discovered in Xinjian. http://www.atarn.org/letters/ltr_nov02.htm, 2002.

[B10] Valeriu Sîrbu. Dacian settlements and necropolises in SouthwesternRomania (2nd c. B.C.-1st c. A.D.). Muzeul Brailei, 2005.

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5. CONCLUSION

[C1] Björn Gerth et al. 3D Modeling for Non-Expert Users with the CastleConstruction Kit v0.5. TU Braunschweig, 2005.

[C2] Maarten Vergauwen and Luc Van Gool, Web-Based 3D ReconstructionService, Machine Vision Applications, 17, pp. 411-426, 2006.

[C3] Marco Andreetto, Nicola Brusco, Guido M. Cortelazzo. Automatic 3DModeling of Archaeological Objects. University of Padova, 2003.

[C4] Hippolyte Mounier. PhotoSculpt Textures. http://www.photosculpt.net, 2010.

[C5] Lukáš Mach. Insight3D. http://insight3d.sourceforge.net/,2009.

[C6] John Cosmas et al. 3D MURALE: A Multimedia System for Archaeol-ogy. VAST ’01, 2001.

[C7] Pavel Zoch. Modelování bronzové sekery od A do Z. http://www.3dsoftware.cz/3dportal/clanek.aspx?id=158, 2005.

[C8] Autodesk. 123D Catch. http://www.123dapp.com/catch, 2012.

[C9] Qi Pan, Gerhard Reitmayr, Tom W. Drummond. Interactive Model Re-construction with User Guidance. Cambridge University EngineeringDepartment, 2009.

[C10] Anestis Koutsoudis. A 3D Vessel Modeller and Random 3D VesselGenerator. http://www.ipet.gr/~akoutsou/, 2011.

[C11] Anestis Koutsoudis, Fotis Arnaoutoglou, Christodoulos Chamzas. On3D reconstruction of the old city of Xanthi. A minimum budget ap-proach to virtual touring based on photogrammetry. Journal of Cul-tural Heritage 8, 2007.

[C12] Jean-Yves Bouguet, Pietro Perona. Weakly structured lighting - Scan-ning using shadows. California Institute of Technology, May 1999.

[C13] Douglas Lanman, Gabriel Taubin. Build Your Own 3D Scanner: Opti-cal Triangulation for Beginners. http://mesh.brown.edu/byo3d/links.html, 2009.

[C14] Marc Pollefeys et al. 3D Acquisition of Archaeological Heritage FromImages. Center for Processing of Speech and Images, K.U.Leuven,2001.

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5. CONCLUSION

[C15] F.J. Melero, J.C. Torres, A. León. On the Interactive 3D Reconstructionof Iberian Vessels. Universidad de Granada, 2003.

[C16] Yifan Lu. Interactive Reconstruction of Archaeological Fragments in aCollaborative Environment. Australian National University, 2006.

[D1] Juan A. Barceló, Maurizio Forte, Donald H. Sanders. The Diversity ofArchaeological Virtual Worlds. Learning Sites Inc., 2000.

[D2] Laia Pujol, Archaeology, museums and virtual reality. Revista Digitald’Humanitats, 2004.

[D3] Nick Ryan. Documenting and Validating Virtual Archaeology. Univer-sity of Kent at Canterbury, 2002.

[D4] Melissa M. Terras. A Virtual Tomb for Kelvingrove: Virtual Reality, Ar-chaeology and Education. University College London, 1998.

[D5] Roberto Andreoli et al. Interactive 3D Environments by usingvideogame engines. ISISLab - Dipartimento di Informatica ed Appli-cazioni, Universit‘a di Salerno, 2005.

[D6] Hrvoje Benko, Edward W. Ishak, Steven Feiner. Collaborative MixedReality Visualization of an Archaeological Excavation. Department ofComputer Science, Columbia University, 2007.

[E1] Virtual Reality. http://oxforddictionaries.com, 2012.

[E2] Jirí Machácek. Pocítacová podpora v archeologii 2. Ústav archeologiea muzeologie Filozofické fakulty Masarykovy univerzity, 2008.

[E3] Gary Lock. Using Computers in Archaeology. Routledge, 2003.

[E4] Adam Finkelstein et al. PatchMatch: A Randomized CorrespondenceAlgorithm for Structural Image Editing. ACM Transactions on Graph-ics (Proc. SIGGRAPH), 2009.

[E5] Wikipedia contributors. Wikipedia, The Free Encyclopedia. http://en.wikipedia.org, 2012.

[E6] Franco Niccolucci, Sorin Hermon. A fuzzy logic approach to reliabilityin archaeological virtual reconstruction. University of Florence, 2004.

A - History, B - Archaeology, C - 3D Data Acquisition, D - 3D Data Processingand Presentation, E - Other

51

Appendix A

Reference material

52

A. REFERENCE MATERIAL

Figure A.1: A.) Mahaira from Neudorf, B.) Dacian sica, C.) Thracian sicas, D.)Dacian mahairas from Oltenia

53


Figure A.2: Thai or Burmese swords from the late 18th century

Figure A.3: Dacian mahaira from Hunedoara,1st-2nd c. BC

54


Figure A.4: Sarmatian ring hilted swords, 2nd-3rd c. BC

Figure A.5: Both sides of the knife artifact

55


Figure A.6: Reference used for the Comati drawing

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Figure A.7: Celtic knife replica

57

Appendix B

Digital archive

The digital archive contains these folders:

• 3D models - Cinema 4D scene files for the arrowhead, knife, mahairaand vessels. Textures, renders and a video turnaround included.

• content aware test - results of my tests of the Content Aware Tool inAdobe Photoshop CS 6.

• finds material - images of archaeological finds used for my reconstruc-tions.

• photogrammetry - results of all tested photogrammetry applications,one sample test photo set.

• popular educational illustration - high resolution version of the paint-ing, reference material used for the painting.

• Sketch and Toon - example Cinema 4D scenes using the non-realisticmaterials mimicking archaeological drawings.

Sketch and Toon materials

For in depth understanding of the S&T system it is advised to study the offi-cial Maxon manual:

http://http.maxon.net/pub/r9/docs/manual_sketch_9.0_us.pdf

The effect of non-realistic rendering is achieved by two main components:

1. In Rendering settings the Sketch and Toon effect is added and its boxis checked.

2. The objects we wish to render have a (at least one) Sketch and Toonmaterial assigned.

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B. DIGITAL ARCHIVE

My base materials for the body of the object are using the Hatch shader inthe Luminance channel. The Hatch shader analyzes the rendered object anddraws a user-chosen texture all over the object. Where the object is supposedto be dark, the shader puts many strokes of this texture, where it’s lighterit draws a smaller amount. I created a dot texture and two line textures. Avariety of materials can be created using those.

Refer to the Manual for detailed settings of the Hatch shader.Several of the materials make use of the Ambient Occlusion effect. In fact,

such a material uses Layer in the Luminance channel, composed of the Hatchshader and another Layer of a Hatch-masked out Ambient Occlusion chan-nel.

This is done to put another set of strokes over the most shaded places onthe model (making them darker and the model easier readable).

Do note that the AO effect needs to be added in Render settings for thisto work. This kind of material also takes a significantly longer time to render.

Depending on the scale of the models rendered, it is necessary to tweakthe tiling options in the material’s tag (Tiles X and Tiles Y) so that the texturestrokes are of the desired size.

Over the base material an outline material needs to be applied. It repre-sents the outline of the object and any other kind of line strokes we set it to.It is important to enable shading in the Shading tab of the line material’s tag,otherwise it’ll ignore the base material underneath.

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Appendix C

Previously created reconstructions

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C. PREVIOUSLY CREATED RECONSTRUCTIONS

Figure C.1: Gestikapoinan - two Lusitanian warriors on watch. 2008.

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C. PREVIOUSLY CREATED RECONSTRUCTIONS

Figure C.2: Hellenistic standard bearer. 2009.62

Documents

Digital Reconstruction of Archaeological Findspospabr.sweb.cz/dpJanPospisil.pdf · This thesis deals with the topic of digital reconstruction of objects and espe-cially its use in