Virtual archeology. Bring new life to ancient worlds
Di Bernie Roehl
Innovation³, N° 40, estate 1997, pagg. 28 - 35.

For centuries, archeologists have faced an awesome challenge.
Working from little more than the excavated ruins of ancient buildings and fragments of various artifacts, they've had to reconstruct an image of what life was like for the citizens of a long-dead civilization. Their task was not only one of digging and collecting and organizing, but also one of creative visualization.
Now, as the end of the millennium draws near, archeologists are finally acquiring a set of tools that allow them to take their mental reconstructions and give them a visible form that can be shared with others. The result is an exciting new field that's come to be known as virtual archeology.
Virtual archeology combines the time-honored techniques of conventional archeology with cutting-edge 3D computer graphics, to bring new life to ancient worlds.

The Purpose of Virtual Archeology

First and foremost, virtual archeology makes it possible for researchers to share their discoveries and insights with their fellow archeologists. Rather than trying to describe an excavated site using words or rough sketches, the entire scene can be reconstructed in three dimensions and explored interactively. As new information becomes available, the virtual representation of the scene can be updated to reflect the additional data. Archeologists can collaborate as never before, working together to build increasingly detailed models of these ancient worlds.
Not only can archeologists share their knowledge with each other, they can also display much of it to the general public. Up until now, the only way for most people to see historic artifacts has been in a museum. A bit of pottery, a necklace, or pieces of clothing may be temporarily displayed in a glass case to satisfy the public's natural curiosity about the distant past.
However, there are serious limitations to such real, physical displays. Most museums have only a certain amount of space to devote to their exhibits, so each one can only remain in place for a short period of time before being replaced. And of course, whenever an artifact is put on display it runs the risk of being damaged or stolen. Even exposing some items to air and direct lighting can cause serious, permanent harm.
By presenting virtual reconstructions of the artifacts and the buildings that house them, all of those problems can be avoided. Since an entire virtual exhibit exists solely inside a computer, there are no limits as to how large it can be. The 3D models of the objects can be left on display indefinitely, and they can be seen in the context of a computer-generated virtual world that matches the historic site in complete detail. None of the original items need ever be exposed to air, sunlight, small children, or the possibility of theft or vandalism.
What's more, these virtual museums can be made available over the Internet. This allows students, academics, and curious armchair archeologists all over the world to have access to the information in a form that's easy to understand. Historic sites that are no longer open to the public, such as Stonehenge, suddenly become accessible to an audience larger than ever before.

Gaining Insights

The sharing of knowledge isn't the only benefit of virtual archeology. The very process of creating a three-dimensional model from the accumulated data will often lead to additional discoveries.
For example, think about lighting. Part of the process of creating a virtual world involves positioning light sources, setting their color, adjusting their influence on the scene, and so forth. This leads the virtual archeologist to ask what forms of illumination were available in the ancient world. By finding the answer to that question, our understanding of what the world was actually like is significantly increased.
Another example involves texture mapping. When a new surface is added to a virtual world, it needs to be assigned some basic color and texture information. That can lead to interesting questions about what types of building materials would have been used, what finishes would be applied to the walls, whether there would be wall-hangings or other forms of decoration, and so on.
So the very process of creating a virtual world will often provoke new and interesting questions, which serve to guide archeologists’ future efforts.

Exploring the Past

Not only do these reconstructions help scholars visualize a world, they can also make it possible for curious adventure-seekers to immerse themselves in complete virtual environments based on long-buried civilizations. Instead of passively looking at relics or artists' sketches, students and historians will be able to wander through an ancient city in real time and experience it the way a citizen of the time would have. The very act of walking the streets of an ancient community will provide greater insight into the society's structure and customs.
Jeffrey Jacobson, technical director of the Virtual Pompeii reconstruction explained, "These reconstructions open the door-not just to the buildings, but to the life that the people lived back then. We can have a sense of people going about their business. In a well-researched project, viewers will experience the weather as well as the natural flora and fauna of the time. The viewer of an historical reconstruction has a rich visual synthesis that would take years and years of study to otherwise build from books and artifacts."

The Challenges

All of this sounds very exciting, but the technical challenges facing virtual archeology are immense. Not only must archeologists do all the things they do now, but they must also work with 3D artists and modelers to construct the sites in three dimensions. Once this modeling work is done, powerful graphics hardware is required to present the world in real time.
Modeling the real world is a daunting task, and doing it based on incomplete and speculative data represents an even greater challenge. However, archeologists around the world are rising to meet that challenge, and the results are truly spectacular.
In order to appreciate the variety of archeological sites that are being turned into virtual worlds, it's useful to take a look at a few examples.

After Vesuvius

Consider the ancient city of Pompeii. The entire city effectively vanished in AD 79, when Mount Vesuvius erupted and buried it under tons of volcanic ash. In many ways, the site is ideal from an archeological standpoint. It did not decline gradually over time, nor was it utterly destroyed as many cities have been throughout history. Instead it was captured like a fly in amber, and has since been reconstructed by enthusiastic researchers.
Under the direction of Carnegie Mellon research fellow Carl Loeffler, sections of Pompeii have been modeled and reconstructed in virtual reality applications. The project was done in collaboration with a number of prestigious academic institutions and leading high-tech companies contributing to the effort. A team of experts from the Archeological Institute of America, faculty and students from Carnegie Mellon’s Drama Department, and Roman Art historians from the Department of Art History at the University of Pittsburgh re-created Pompeii's Theater Complex and the Temple of Isis, among other constructions from the ancient city. The virtual reality scenes allow viewers to experience a range of Pompeiian life and culture - which was woven from Greek roots underscored with the Roman Empire and the Mediterranean communities.
The Theater Complex reconstruction includes the Large Theater, the Temple of Hercules, and the Triangular Forum. The reenactment of a typical theatrical performance at the Large Theater is a special feature available in the simulation. One enters an open air amphitheater and views an authentic theatrical performance.
In another reconstruction, viewers can explore the Temple of Isis’ colonnaded walkways, courtyards, architectural structures, sculptures, and colorful murals, reproduced in amazing detail. The sense of reality is heightened by animated figures, such as a chanter and a flutist, and by the audio track. The chanting character is speaking in Latin when first observed at a distance. As the viewer draws closer, the chanter switches to English, creating a dynamic world for modern-day viewers to understand and experience. The same technique is used for a plaque upon the wall of the Temple of Isis. When seen at a distance, the plaque appears to he written in Latin. As the viewer moves closer, the plaque changes to English.
Virtual Pompeii is produced and displayed on the Silicon Graphics Onyx series. There are two ways to explore the virtual space-individually or as part of a group, Assisted by museum staff, one person at a time will be allowed to take a turn wearing a head-mounted device. When the user's head moves, the computer dynamically changes the view. By manipulating a trackball, the user navigates through the space. Everything the user sees is projected onto an overhead screen that can be seen by others in the gallery.
Virtual Pompeii has been displayed at the M.H. de Young Memorial Museum of Art in San Francisco as well as other art and science museums internationally. It will be exhibited at the Smithsonian in Washington, D.C., beginning in the summer of 1998 Numerous images from Virtual Pompeii can be found at http://topaz,rec.ri.cmu.edu/files/gallery/pompeii/theater.html.

The "Soldiers of Xian"

The vaults of Emperor Qin Shihuang's terra-cotta warriors have been called the eighth wonder of the world. The original Xian site, which had thousands of life-size tetra-cotta warriors and horses buried underground 1.5 km away from the Emperor's Mausoleum, was excavated in 1975.
Professor Nadia Magnenat Thalmann, head of the Miralab at the University of Geneva and world-renowned for her work with virtual humans, is currently directing the reconstruction of a group of the Xian terra-cotta soldiers. Thalmann gave a brief glimpse of her soldiers at the Virtual Heritage Conference in London in late 1996. Thalmann demonstrated vignettes of the Xian reconstruction that show a number of the terra-cotta warriors awakening from sleep.
One didn’t have his terra-cotta head, but it was retrieved from the floor nearby and put on his neck for him by another soldier. Both looked pleased and marched off together out of the tomb. At that time, the soldiers were not fully autonomous, nor were they fully programmed. They could perform sequences of actions such as walking.
Images from the movie The Soldiers of Xian can be seen on the Miralab Web site at http://miralabwww.unige.ch/Java-Less.html.

The Temple of Tenochtitlan

The Aztec capital of Tenochtitlan was a remarkable place before it was destroyed early in the 16th century by Spanish conquistadors. It was a major urban center of trade and commerce.
The Aztecs were deeply religious. At the center of Tenochtitlan stood the Great Temple, with shrines to the gods of sun and rain. Not far away was the Temple of Quetzalcoatl.
Unfortunately, this beautiful city is no more. On the site where Tenochtitlan once existed is modern-day Mexico City, and it's almost by chance that the ruins were discovered during the construction of a new subway tunnel.
The temple and some of the surrounding buildings have now been recreated as a virtual world that can be explored in real time over the Internet. In fact, this particular world was created by Delle Maxwell and used as an example in The VRML 2.0 Handbook by Jed Hartman and Josie Wernecke of Silicon Graphics, published by Addison-Wesley Longman, Inc.
The world not only demonstrates accurate geometric representations of the various buildings, but also the use of sound and text to enhance the experience.

The Vari House

Perhaps one of the most accessible archeological worlds on the Internet is the Vari House, created by Learning Sites Incorporated. The Vari House is located in southeastern Greece, not far from the Aegean Sea. It was originally home to a family of beekeepers, and Learning Sites even managed to show an example of one of them hard at work tending his hives.
The house itself dates back to approximately 300 BC in Greece's Hellenistic period. The Web site shows the current ruins as well as the full house, showing how little information an archeologist often has to work from.
The Vari House illustrates how virtual archeology can be used for educational purposes. The Web pages associated with it ask as many questions as it provides answers, and thus encourages the readers to think about the available information and draw their own conclusions in much the same way that an archeologist does.
Vari House was selected by Silicon Graphics, Inc., as one of the top 10 VRML virtual world packages. Learning Sites, Inc., (www.learningsites.com) bills itself as the creator of "digitally reconstructed worlds for interactive education and research." Its professional services include the 3D reproductions of sites (such as Vari House). It will also digitize and produce 3D models of historical artifacts for archeologists.

Infobyte's Historical Reconstructions

Infobyte SpA, based in Rome, and CNR (Italy’s National Research Council) have developed a number of virtual reality reconstructions that have won international recognition and acclaim from cultural institutions and computer-industry professionals alike. Infobyte uses Onyx2 and a special proprietary software technology (PICTEL) to depict scenes from art history or archeological sites.
The St. Peter's Basilica virtual reality project from Infobyte allows a unique experience in that users can visit both current and ancient versions of the Basilica. Viewers can explore the reconstruction of the interior of the current Basilica and walk outside within the area enclosed by Bernini's colonnade. They can also visit the long-gone Constantinian Basilica and its external cloister, both of which were demolished in the 16th century, to make room for the current structure.
The City of Giotto from Infobyte is a high-definition virtual reality experience that enables the user to visit the Basilica of St. Francis in Assisi. The visitor can pass through the wide nave of the church and look at the frescoes by Giotto that decorate the waft. Most spectacular is the fact that the virtual visitor can enter Giotto's frescoes through the walls on which they are painted and explore the re-creations of the three-dimensional buildings that the painter drew in his frescoes.
The Nefertari Light of Egypt reconstruction from Infobyte enables viewers to "see" the tomb of Nefertari without entering the actual fragile environment. The director of the Ghetty Conservation Institute has commented on the invaluable nature of this virtual reality project. "We can allow people to visit the tomb without exposing it to irreversible damage." The visitor can move from any point and has three-dimensional vision, which contributes to the sense of full immersion. The visitor can also listen to the voices of the characters and the ritual texts depicted in the hieroglyphics that cover the walls.
These three projects from Infobyte use the Fakespace BOOM3C, which capitalizes upon the natural motion of the body-thereby increasing the user's feelings of movements through the virtual space. The user puts her face against BOOM's faceplate, which is suspended on the end of an arm that moves smoothly in conjunction with the user's direction of view. The motion of the user's head, neck shoulders, and back in alignment with the virtual image orients the user within a visualization. These and other Infobyte projects can be seen at www.infobyte.it.

The Future

As computer graphics power continues to increase, it opens up an even more exciting possibility. Instead of simply wandering through ancient worlds, we will immerse ourselves in them. We will be able to recreate the daily life of people who actually lived in Pompeii or Tenochtitlan. We will create interactive adventures that are both enjoyable and educational, which will serve to give us an even greater insight into those great civilizations of the past.
As Onyx system-level graphics capabilities begin to migrate to everyone's desktop, we may soon be able to share in the exploration of virtual worlds built around historic sites hundreds or thousands of years old. Archeology itself will be transformed, as will the public's perception of the science. Long-dead civilizations will suddenly spring to vibrant life, as the technological wonders of the modern world give us access to the glories of our distant past.

Additional Resources

One excellent book on this subject is Virtual Archeology: Re-creating Ancient Worlds, edited by Maurizio Forte and Alberto Siliotti, translated into English and published by Harry N. Abrams Inc. in 1997.
- For the past couple of years the British journal VR News has co-sponsored a conference called Virtual Heritage. The home-page for last year's conference is www.dircon.co.uk/heritage/virtual/index. html

• The VR News Web site is www.vrnews.com
• Manchester Metropolitan University
• www.doc.mmu.ac.uk/STAFF/B.Mitchell/research.html