Issue: Volume: 25 Issue: 8 (August 2002)

Roamin' Ruins

By Jenny Donelan

One August day in 79 AD, Gaius Julius Polybius, a mover and shaker in Roman society, met his match when Mount Vesuvius erupted, heaping eight to ten feet of volcanic ash, cinder, and rock onto his spacious villa, obliterating it and the rest of the resort city of Pompeii. The Polybius house, and the town, lay silent for nearly 2000 years, until they were unearthed in recent centuries. Because Pompeii came to such a sudden end, it serves as a sort of time capsule that tells us much about the daily lives of the ancient Romans. Not only paintings and statues, but loaves of bread and household pets were preserved by the volcanic conditions that visited the town-eerie reminders of how quickly everyday life can come to an end.

It was this idea of showing how things stood directly before the eruption that spurred researchers at the University of Tokyo and the Soprintendenza Archeologica di Pompei in charge of the site to create a virtual reconstruction of a Pompeiian house, and to allow visitors to "tour" the dwelling. Julius Polybius's house was chosen in part because it had been physically reconstructed inaccurately, mostly with an eye toward preserving it from atmospheric decay. By merging not only survey data from the site, but journal entries and sketches made at the time the house was excavated in the 1960s and '70s, researchers hoped to convey a more accurate idea of how the villa would have looked immediately before the volcano blew.
Using excavation notes, sketches, photographs, and other sources, multimedia firm Altair 4 created a 3D walkthrough of a luxurious villa that once belonged to Roman nobleman Julius Polybius. The villa was destroyed, along with the rest of the town of Pomp

The research teams chose the Italian multimedia specialty firm of Altair 4, which had already created "Ancient Rome Tour," a DVD-ROM with 3D restorations of the city's important ancient monuments, to handle the digital end of the project. Managers Stefano Moretti and Pietro Galifi headed up the effort for Altair 4, which received a variety of data from the researchers, including an archeological survey with plans in 1:50 scale, books, journals, and a series of new photographs taken at the site. "The house had different building phases," says Moretti, "but we chose the last one, which was closest to the eruption." Merging all this information in an accurate way was one of the greatest challenges of the project, he notes.
Mount Vesuvius, which loomed over the Roman resort town of Pompeii, caused most of its damage not with flows of hot lava, but with a deadly cloud of dust, ash, and rock.

Three different groups at Altair 4 worked respectively on the modeling of the house, the modeling of the furniture and other objects within, and the textures. Artists used Discreet's 3ds max to model and render the dwelling, Adobe Systems' Pho toshop to "paint" the frescos on the walls, and Onyx Computer's Tree Storm, a parametric plant generating program, for the trees in the house's atrium. Hardware support included nine double-pro cessor workstations, including four lent by AMD for the rendering phase of the project, which were powered by AMD 1.5ghz Athlon processors
The movie shows how the cloud from the volcano quickly spread over the town of Pompeii (top) and the villa (bottom). In order to simulate the pyroclastic flow, the artists used Cebas's PyroCluster software.

"From a technical point of view," says Moretti, "the most interesting challenges were the reconstruction of the plants in the garden and the dynamic pyroclastic fluid [from the erupting volcano]." The trees were based on paleobotanic research from the Soprintendenza Archeologica di Pompei, and the eruptions were based on traces of volcanic flow in the area, and simulated using Cebas's Py roCluster plug-in for 3ds max. For this last task, says Moretti, "There were really too many parameters. We had to make several tests before we obtained satisfactory results." Long calculation times were also a burden, he adds.

"The House of Julius Polybius" premiered at the University of Tokyo and made the rounds of North American museums and colleges, including the Smithsonian and Princeton University, this past spring. The 12-minute film draws the viewer through an unoccupied house that is large and elegantly, if somewhat sparsely, appointed. A breeze that seems to hint at a storm to come ruffles draperies, as well as the leaves of the trees in the atrium. The number of rooms, the graceful furniture, and the intricate frescos depicting nature scenes convey that the house's owner was a person of means. When the eruption begins, the sky turns dark. A cut to a bird's eye view of Pompeii shows the gray dust cloud swiftly spreading over the city. Outside, ash piles up on the house, and inside, silhouettes of humans-Julius Polybius and a young, pregnant woman, thought to be his daughter, appear briefly before fading to photographs of their skeletons found amid the ruins.
When the eruption was over, eight to ten feet of ash had settled on the Polybius villa. Researchers determined that the weight of the material that settled on the structure eventually caused its roof to collapse.

The lack of people in the film was perhaps the greatest disappointment of the project, notes Moretti. Time constraints kept Altair 4 from animating the inhabitants. As an alternative that would at least hint at the lives that ended within the house, artists inserted plaster casts of faces into the footage, along with shadows of running figures against the flickering backdrop of courtyard walls. Voices call out and people are heard running in the background. Eventually, the weight of the ash collapses the roof of this once-proud house and all goes silent. Photographs of the ruined structure appear at the end of the film. The elegant house through which we have just virtually roamed has become physical ruins.

Jenny Donelan is managing editor for Computer Graphics World.