Maurizio Forte AIACE International Association of Computing in Archaeology
Antonella Guidazzoli CINECA VISIT Visual Information Laboratory
About Virtual Archaeology
"Towards a virtual archaeology" is the evocative title of an article published by Paul Reilly in 1991. In it he describes some of the possible courses that might be taken by the archaeology of the future - an archaeology we can imagine as being essentially technological, multidisciplinary and virtual (in the scientific sense of the word), because it will be linked into the fields of computer processing, simulation, experimentation and computer reconstruction. But will the archaeology of the future be like that ? What language will it be using in the third millennium ? What will its fields of investigation be ?
Above all, how much of the ancient world will be able to reconstruct from the remnants of its material culture, sites and buildings ?
The possibilities that are increasingly being created by scientific and technological research have opened new horizons for archaeology and redrawn its boundaries. As progress marches on , we will be able to reconstruct ever larger segments of our most distant past, leading to a more accurate understanding of the macrocosm of the ancient world. The problem for archaeology is to retrieve the maximum possible amount of information from the material culture, so as to recapture its non-material aspects as well.
However, this process of amassing and interpreting information is a continuous one; what we cannot find out or understand now, we will be able to comprehend in the future - provided we do not destroy or lose the underlying data. It is important, therefore, not to waste information or lose access to it. In this process of acquisition , restoration and re-presentation the assistance of computers and other technology has become vital, and it is here that the term virtual archaeology becomes valid. The archaeology of the third millennium will very likely be a science with a strong technological element that will enhance out of all proportion our ability to explore, to interpret and to classify, bringing with it a greater and more penetrating ability to reconstruct the past. Loosely speaking, it will be a computerized archaeology, because it will involve the large-scale use of computer and archaeometric science in a major scientific endeavour to develop a truly virtual research laboratory. The "quality" of archaeological information and classification will in future create the bases of a new cognitive science.
Excavation and fieldwork are sometimes rather embarrassing for the archaeologist, because (paradoxically) they involve partially destroying the site that is the object of research without ever being able to recapture the whole of the information it contains. In the course of exploration the archaeologist destroys stratigraphy and structures and removes large quantities of soil in order to be able to interpret the excavated remains; "seeing what’s underneath is essential for interpretation, but it never provides a whole answer. In many cases - including the cities richest in history - ancient structures hide yet earlier structures. Troy, for instance, had at least nine main phases dating between 3000 bc and the Roman period (Troy IX), and other phases again dating to the Late Antique and subsequent periods. Each one of these phases describes and represents a different city, and each would become intelligible to archaeologists only after thorough investigation - and yet this would have to involve the removal of overlying structures from later phases. Stratigraphy represents an extremely varied and complex sequence of innumerable pieces of information that are often difficult to identify - but not one of them is insignificant, and (ideally) not one should be destroyed.
Archaeological excavation is therefore a complex process that, if carried out correctly, allows a reconstruction of past events - or of a small part of them. That is the constant problem of archaeological research. Only a small amount of intelligible information can be recovered from the ground - a minute percentage of classifiable "events" at a site - and the very activity of excavation inevitably involves some degree of destruction of the information that is buried.
A banal example: how much information do changes in the architecture or furnishings of one’s own house (or even the living-room or bedroom) contain about what has taken place in it ? Only one’s own memory can reliably record all that has happened there, for few of the actions and events will have left visible traces: the changed position of a piece of furniture, a mark on the wall or a chipped tile. If our house is destroyed, an archaeologist investigating its remains in the distant future will be able to reconstruct very little of what took place in it. If no related documents have been found, he or she will find it very hard even to work out which rooms was which (without the furnishings, how do you distinguish a living- room from a bedroom ?).
Therefore, the ability to reproduce virtually the whole exploratory phase of archaeological research is the decision-maker’s tool that enables us to answer the question "How much do we reconstruct ?" It is perhaps our only means of refining ever more accurate classifications and interpretations. It therefore also represents the last stage of research: the recreation of an ancient space, including even its most esoteric aspects - not arbitrarily and unchangeably, but virtually.
The methods at the disposal of archaeology - first put on a scientific basis when it enlisted the aid of information science and computers in the 1960s - can now justifiably be called multidisciplinary, because they span so many areas of the applied sciences. The interaction between research in archaeology, geology and the physical, natural and information sciences is now providing an ever firmer methodological foundation. However, one of the great goals of archaeology is to be presenter (or re-presenter) of information - of what we can be deduced and extrapolated from its data and finds.
Alongside research, therefore, it has an equally important role of communication and dissemination to develop. Amongst the many fields of research, archaeology -synthesizing the most disparate hypotheses in an all-embracing scientific attempt to reconstruct the past - is one of those best able to capture the imagination of the public.
Why is the virtual reconstruction of an archaeological site so important ? Because, over and above its strong popular impact, computer reconstruction allows the presentation of complex information in a visual way that enables it to be used to test and refine the image or model that has been created. It is very much more than a graphic reconstruction: it is a simulation. And, because it is a simulation, it provides a non-intrusive and non-destructive means of exploring a model in three dimensions and from an infinite number of viewpoints. Furthermore, it allows objective verification to be made of possible interpretations of architecture, material culture, topography, palaeo-environmental data, restoration, museum display, and any number of other factors.
The ancient world that could be explored by virtual archaeology is a world in color - very different from the monochrome world to which earlier reconstructions have accustomed us. The polychrome renderings of building materials - from Parian marble to wood, from stone to travertine, from limestone to terracotta, and so on - convey the colour and texture and vitality of the architectural finishes and the ancient buildings they adorn.
All these factors make virtual archaeology a highly useful tool for enlarging our knowledge of a field that has hitherto been under-explored, perhaps because it is concerned with the past.
In April 1995, at "Technology, Instruments and Applications", the third International Conference on the World Wide Web (now the major element of the Internet, the world’s largest digital network), a new graphics language was presented: VRML, Virtual Reality Modelling Language. VRML is a language that describes three-dimensional objects and allows the user to move from texts into three-dimensional spaces and vice-versa. It is a completely new way of visualizing information in three-dimensional space via hypermedia links, allowing the information/objects to be rotated, moved and observed from any angle. This powerful graphic language opens up new and extraordinary possibilities for handling multimedia data in three-dimensional form.
We think that in the near future archaeological information will be available in VRML format, offering the opportunity of exploring for instance virtual archaeological parks furnished with physical and conceptual models, with finite territories and multidimensional ideas.
A computing environment for Virtual Archaeology: VISIT Visual Information Laboratory
CINECA is the most important Italian supercomputing center for public and private research activities and one of the world’s majors. A Consortium gathering 13 Italian Universities (Ancona, Bologna, Catania, Ferrara, Florence, Modena, Padua, Parma, Siena, Trento, Trieste, Udine, Venice), it was established by law in 1969 and is managed by a Board of Directors, including the Rectors of the member universities and a representative of the Ministry for University and Scientific and Technological Research.
The involvement of CINECA at the European level, through the EU research projects TMR, MAST, ESPRIT, ENVIRONMENT, ICARUS TENTELECOM must be mentioned. CINECA is part of these projects by making the resources of supercomputing available to European partners.
Alongside the traditional fields of physics, chemistry, engineering (non-linear structural analysis, fluid dynamics, aerodynamics) at present the perspectives of supercomputing also concern so-defined "non-traditional" sectors, such as biomedicine, cultural heritage safeguarding data-mining. Supercomputing can also be applied to human sciences. For example, computerized archaelogy provides today new survey possibilities towards the discovery of archaelogical sites that might otherwise remain unknown. Finally, data mining: thanks to the possibility to analyze an enormous amount of data and to detect even their slightest and most unforeseeable correlations, it opens up new horizons in knowledge and survey. All these techniques require very complex algorithms that in turn involve a large amount of computing.
VIS.I.T an interdisplicinary laboratory dedicated to supporting visualization of massive or complex numerical data to users is also available at CINECA.
The results of the simulations running on the CINECA supercomputing environment are post-processed here. In fact, the laboratory staff consists of people of the CINECA Supercomputing Group. Also large amounts of data coming from other research centers are being visualized by VIS.I.T using an SGI supercomputing graphic machine ONYX 2 The lab facility offers the possibility to produce final results on videotapes, transparancies or World Wide Web formats. Moreover, instruments for multi-media navigation through scientific data are developed here, that can be interactively steered by end users.
Morever VISIT Staff is we often involved in European Community projects. All our activities are focused on our mission statement, to provide useful tools for analyzing and understanding scientific data to public and private research institutions in Italy.
The lab is conceived as an open space room with SGI workstations, connected with the Cray C90 vectorcomputer and the Cray T3E massively parallel computer of CINECA by a high-bandwidth interconnection. Further ifrastructure include instruments to produce videotapes, high quality transparancies, and end user software.
The staff consists of people of the CINECA Supercomputing Group, who coordinate the work of their numerous collaborators. During the past years, some 15 European researchers worked together with us, apart from a lot of PhD and MsC students.
The laboratory organizes an annual program of courses and seminars to convey information to academic researchers. Future courses include scientific visualization, applications of computational archaeology and medical image processing.
Applications of Virtual Archaeology
Currently the main research activities performed at VISIT in the field of Computational Techniques for Archaeology are currently devoted to create a system for reconstruction, visualization and fruition of 3D archeological sites, virtually explored from the users in locally (CD ROM) and on Internet by VRML and JAVA languages.
We provide the reconstruction of the archaeological models and we study the hypermedia interface navigation, as already experimented in the case of Verucchio Museum (Rimini, Italy), where a PC work- station is integrated with a multimedia system of 3D navigation.
The models reconstruction provides distinct output for typologies of sites and for archaeological landscapes. In the first case monuments the 3D reconstruction of the tombs (e.g Etruscan Tombs of
Tarquinia) is performed by the follwing steps:
digitalisation and processing of images and documentation;
vectorial digitalisation and wire frame models reconstruction;
color sampling and textures analysis for the restoration of the original chromatic components;
virtual restoration and integration of the paintings;
texture mapping of material and photographs;
rendering.
In the second case (archaeological landscapes) the reconstruction of the archaeological landscapes (eg. the Reno Valley Bologna Italy , Rock of Entella Sicily, Jaen Spain ) the working steps are the following:
DTM creation (digital terrain models) in macro-scale (with cartographical data) and in details (microscale) using a laser tacheometer;
texture mapping of the aerial photographs and of the satellite images on the DTM;
3D integration with GIS data;
solid modelling in macroscale ;
multimedia processing of information for describing the landscape such as a virtual archaeological park;
multimedia processing (video, images, databases, graphics) of hyperlinks connected to the archaeological structures;
multiuser interface creation for Internet navigation into 3D archaeological models
Archaeological Landscape Navigations : archaeological sites location : Jaen Spain
Recent Publications by the authors:
Forte M., Guidazzoli A. Archaeology and desktop virtual reality: experiments and applications CAA 95, Leiden University
Progetto per l'elaborazione 3d di immagini video archeologiche in Atti del III Convegno Internazionale di Archeologia e Informatica, Roma, 1995, in stampa in "Archeologia e Calcolatori 7, 1996.
M.Forte, A.Guidazzoli Archeologia computazionale tra Visualizzazione Scientifica , Computer Vision e Realtà Virtuale Technographics num. 6 pp, 36-41 1995.
Guidazzoli A., Gutierrez Soler L.M., Alcazar Hernandez E.M. M.A., Royo En- carnacion M.A., Elaboracion de un modelo de navegacion tridimensional sobre el paisaje arqueologico de Jaen in Arquelogia y Territorio medieval Universidad de Jaen 1995, pp.117-187 .