Perception of Pompeii frescoes under realistic illumination simulations
Department of Computer Science
University of Bristol, Woodland Rd, Bristol BS8 1UB
The use of three dimensional computer reconstructions in archaeology is becoming more commonplace with the growth of electronic media and the availability of modelling software. Many of the images generated are photorealistic, but although they may look "real" their validity cannot be guaranteed as no attempt has been made to use physically accurate values for the light sources and surface reflectances. They owe more to an artist's imagination than to an interpretation based on numerical simulation. The commonly used software packages base the lighting conditions on daylight, fluorescent light or filament bulbs and not the lamp and candlelight that would have been used in the past. In some cases the reconstructions are lit with physically impossible lighting values. On the other hand, accurate lighting simulation allows the viewer a perception of a site and its artifacts in close approximation to the original environment.
The House of the Vettii in Pompeii is one of the best preserved and decorated buildings in this World Heritage site, and is the most frequently visited building in Pompeii. The rich colours and extensive use of artistic techniques along with its magnificent state of preservation draws millions of people through its rooms each year. However, the impact of tourism on such a site has led to serious deterioration. Computer reconstruction of the House of the Vetti allows us not only to "restore" the frescoes back to their original colours, but also to view it as it might have been when it was in use by the Vetti family before the eruption of Vesuvius in AD 79.
This paper describes how, by using photographic records, CAD modelling packages and luminaire values from a Spectroradiometer, a three dimensional model can be created and then rendered in Radiance, a suite of programs specifically designed as a lighting visualisation system. This provides us with images that go beyond photorealistic, accurately simulating light behaviour and allowing us a more valid view of the reconstructed site.
Further information is detailed at http://www.cs.bris.ac.uk/~devlin/pompeii/pompeii.html