The computer archaeologist Sophisticated 3D modelling can tell us as much about buildings of the past as it can depict those of the future
Historic architecture and high technology may not always be seen as comfortable bedfellows, but in an increasing number of projects state- of-the-art visualisation technology is being used to inform those carrying out work on historic buildings.
Computer visualisation is increasingly being used in archaeology, with some of the world's most ancient buildings being depicted as 3D models, which can be explored by scientists and historians to provide an insight into the past. Although virtual reality often focuses on generating new environments, much has been discovered about the technology of the Egyptians, Greeks and Romans by reconstructing their greatest works in cyber space. An example of how this can excite the public's imagination was the recent tv series that modelled the seven wonders of the world, and placed them in context using live action footage.
Visualisation not only provides historians with research material but can also inform those seeking to conserve or restore buildings. One example of this is the project under way to build an incredibly accurate model of the Sagrada Familia church, Gaudi's tour de force in Barcelona. The project to visualise the building, whose own completion date is uncertain, is a massive undertaking. Every aspect of the building is being modelled in fine detail from hundreds of photographs, sketches and survey information. The final model will consist of over 22 million polygons, making it one of the most complex single models ever created.
One would expect this type of endeavour to be driven by an architect, but it is in fact the brain-child of Spanish film director Toni Meca: the model will be used in a film next year about the completion of the temple.
Thousands of hours of research, thousands of photographs and constant visits to Catalunya en Miniatura, which housed a scale model of the completed temple, were needed to produce the computer model, which allows us to experience the building in ways impossible to convey with drawings alone. Much of the technology used to achieve this creation was borrowed from the film effects industry. While 3D photo-realistic architectural modelling has yet to become commonplace, the film industry has pushed the technology more than anyone else.
Another example of the use of visualisation technology to provide an insight into an architect's vision is the computer model of the San Marco library in Florence by cadVenture. The original church of San Marco was built in 1299 by Silvestine Monks and was largely reconstructed under the guidance of architect Michelozzo during the fifteenth century. The artist Ben Johnson was commissioned to paint the interior of the library. Instead of undertaking a sketch process Johnson, with the help of Hugh Whitehead, created a virtual space from which views could be used as the basis for the final paintings. The 3D modelling of this space led to some remarkable discoveries.
Neither Ben nor Hugh had ever visited the library, so their experience of the space was through photographs and drawings. When the model was finished neither modeller was happy with the columns, which had been modelled as simple cylinders. Once the entases on the column shafts had been added, the rendered views looked much more realistic.
The use of a computer model, allowed far more exploration of the structure than would have been possible by standing in the building. During the process of altering the columns it also became apparent that the column bases seemed too thin for columns of this size. Some detective work resulted in the discovery that the original floor was in fact lower than the current one. Once the new floor had been removed in the model the renderings showed the complex proportioning system used and the harmonious visual results it produced.
When the building was constructed, a line of high-level windows was present on the west wall of the building, mirroring those on the east. Once the model was complete Hugh and Ben recreated these windows and rendered a series of daylight studies of the interior based on the original design. When the model was placed in geographic space, and the path of the sun modelled, it was revealed that the north-north-east orientation meant that direct light from the newly opened-up windows only penetrated deep into the interior in the afternoon
Companies such as Silicon Graphics are working on specialised vr systems for use on such projects, and new software will soon make the process of creating these virtual worlds much more straightforward.