Interpretation And Applications

During the research phase, once areas of interest have been identified through examination of archives it is not uncommon that recourse be made to the original context. For example, if studying the tooling used to make particular inscriptions, it would be impossible to measure a cross-sectional profile of an incision from a drawing. With accurate 3D data, cross-sectional profiles showing the incisions are straightforward to achieve. Additionally, more standard measurements may also be required, ranging from 'how big is that feature?' to 'how deep are the incisions at that point?' For research purposes, a 3D model is almost ideal in that the full three-dimensionality of the art can be examined in an interactive manner without repeated revisiting of the original site.

Monitoring Decay

Our Palaeolithic heritage is in constant danger of disappearing forever where such heritage is accessible and potentially open to vandalism or other detrimental natural processes. One of the major problems with this critical issue is qualifying what processes are at work on any given context and quantifying exactly how much erosion or accretion there is. Depending on the rock substrate onto which the artworks are made, the processes might include weathering, delamination, disaggregation of the surface or even accretive build-ups through water deposit. None of these processes is easily spotted unless a substantial piece of the artwork is damaged or lost.

High-accuracy 3D scanning may offer a solution to this issue in that it is possible to exactly measure the difference between two scans of the same object. That is, if an artwork is scanned at high resolution and rescanned five years later, a 'difference map' of the two scans can be produced. The difference map can show both exactly where the differences lie and exactly how much difference there is. In the case of delamination, the differences should be fairly substantial, whereas the slower weathering process would only show a minor difference.

Non-Contact Replica Production

The final issue that this chapter discusses is that of creating replica archaeology for visitor interpretation, access, and conservation management. This process has been used to date at several Palaeolithic sites in Spain including Altamira.

As laser scanning produces a highly accurate and objective recording in three dimensions, we can directly use these data to mechanically produce a virtually perfect copy of the artwork in question. The main benefits of this approach are twofold: (a) the reproduction is exactly the same as the original (although manufacturing perfect scale copies is straightforward); (b) the reproduction is completely non-contact. The art is not touched either during the scanning process or during the manufacture of the replica.

As such, this technique offers a real possibility of satisfying the various demands on conservation management schemes for access to relatively inaccessible Palaeolithic artworks.

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