Visualization (Archaeology)

Though difficult to refer to as a discreet area of activity, visualization might best be understood as the method by which archaeological ideas can be effectively communicated to their target audience, which entails obvious overlaps with the functionality of many of the tools mentioned already. It may be useful to think about the growing interest in complex visualization techniques in the context of the post-processual view of archaeology, an approach which gives the human element a central place in the research process and deals with concepts of human defined boundaries and territories. This trend developed in reaction to the deterministic and functional (processual) views prevalent in the discipline prior to the 1980’s, which inclined researchers towards scientific methods (archaeometry). By placing human activity and intervention more at the centre of the research process, there are greater incentives to realise past scenarios using proximal representations of realistic environments, using human scales of reference and, in some cases, indications of human behaviour to enhance interpretations and comprehension of otherwise rather sterile-looking landscapes.

Fig. 3 Visualizing a Prehistoric Landscape - The River Arun (Wessex Archaeology)Fig. 3 Visualizing a Prehistoric Landscape - The River Arun (Wessex Archaeology)

One highly developed example of this approach was demonstrated at CAA UK 2007 by Tom Goskar (Wessex Archaeology), who showed the visualization of the now-submerged landscape that would, in prehistoric times, have formed the mouth of the River Arun. Vibrocore tubes were pushed into the seabed to extract layers of ancient soils which were then analysed to determine what kinds of vegetation would have been present during the period in question. Geophysical survey techniques were used to identify geological layers and terrain modelling software established the physical appearance of the study area. Informed guesses were made about the properties of the surrounding landscape and vegetation and weather systems were created based on the evidence from the vibrocore samples. Human presence was introduced into the visualization using Poser (http://www.e-frontier.com/go/poser) software, which allowed the modellers to create plausible scenarios where adult characters are shown teaching children hunting skills, and children and older-looking figures are shown playing and relaxing on the banks of the river (see fig.7). Combined with a voice-over narration, the end result is a three minute animated representation of what it may have been like to inhabit a long-submerged environment, based on as much evidence as could be gathered to lend verisimilitude to the visualization.

The reinforcement of the gigantic scale of certain types of ancient architecture was one useful outcome of the Pompey Theatre Project, undertaken by Richard Beacham and colleagues, based at the King’s Visualization Laboratory. The Pompey Theatre was constructed in 55 B.C. on a site in Rome that is now occupied by the Campo Marzio and its surrounding buildings. Based on extensive archaeological work and previous reconstructions dating from the nineteenth and early twentieth centuries, tools including 3D Studio Max and SoftImage XSI, were used to model views of the enormous theatre structure, establishing in the process that the columns that form the backdrop to the stage would have dwarfed the human figures taking part in performances.

Fig. 4 Visualizations of the Pompey Theatre, Rome (© King's Visualisation Lab, King's College London)Fig. 4 Visualizations of the Pompey Theatre, Rome (© King's Visualisation Lab, King's College London)

The scale of the architecture can be fully appreciated using the freely downloadable TurnTool viewer, which allows the user to walk, pan, zoom and move around the reconstruction.

The formulation of standardised approaches to demonstrating and incorporating the evidence-base for visualizations has been widely debated recently and one of the results of this discussion has been the establishment of an initiative named the ‘London Charter’ (http://www.londoncharter.org/). This collaborative group is interested in a range of issues surrounding the use of 3D visualizations, including methodologies of practice, standards, the integrity of source material and sustainability and access questions.

Another research area in the field of 3D reconstruction of archaeological evidence involves the investigation of realistic lighting schemes for internal and external spaces. Predictive lighting techniques adjust the environments shown in 3D visualizations to take into account more plausible renditions of how the surroundings may have been perceivable to contemporaneous characters. One open source tool that can be used to simulate potential light values is called Radiance. With this command line driven system, users can specify coordinates and take advantage of the ray tracing functionality to produce output as colour images, numerical values or contour plots.

Fig. 5 Simulation Viewed under Olive Oil Lamp, with Furniture to Show Shadow Effects (Kate Devlin, Alan Chalmers, Duncan Brown)Fig. 5 Simulation Viewed under Olive Oil Lamp, with Furniture to Show Shadow Effects (Kate Devlin, Alan Chalmers, Duncan Brown)

There are important applications for the visualization of objects as well as environments and landscapes, as can be seen at the University of Birmingham VISTA Centre, where a 3D representation of the contents of a sealed canopic jar can be displayed on a Powerwall system. This very large back-projected wall-sized screen enables the display of geometrically accurate stereoscopic images, and in combination with the use of active stereo glasses, provides users with an extraordinarily convincing feeling of the three dimensional presence of the object. Other equipment at the VISTA centre includes immersive screen technology and a haptic workstation featuring Reach-In technology, allowing users to experience two and three dimensional touch-enabled applications.

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