Advanced Techniques for Fast and Accurate Heritage Digitisation in Multiple Case Studies

Abstract

All elements of heritage are exposed to more or less predictable risks. Even though they are in a good state of conservation with economic support for their repair or maintenance, they can suffer sudden accidents leading to their imminent destruction. It is therefore necessary to safeguard them in all scenarios, regardless of the respective scale or state of conservation. That process must at least be based on complete and accurate 3D digitisation. The evolution of devices, software/hardware and platforms nowadays allows such information to be gathered in a sustainable manner. Various existing resources were tried and compared at several heritage sites of different scales with dissimilar risk and protection, following the guidelines of different ICOMOS (International Council on Monuments and Sites) committees. Each case study addresses the choice of digitisation techniques and the characteristics of the end product obtained. The most suitable modality for each situation is analysed, depending on different factors such as accessibility and risks faced. Although the 3D laser scanner is clearly a very fast and very accurate resource, automated photogrammetry is one of the more accessible and affordable resources; along with the potential of UAVs (unmanned aerial vehicles), this enables the digitisation to be sustainably completed.

Photogrammetry as a New Scientific Tool in Archaeology: Worldwide Research Trends

“…Spanish research in the field of photogrammetry for archaeological applications, led by the University of Salamanca, is most successful in the use of drones or UAVs as an effective and low-cost tool [22]. One of the first works in this sense was in the archaeological modelling of a Jewish tannery in Avila [69].…”

“…Therefore, UAV photogrammetry can be understood as a low-cost analytical tool. It has been used in many situations where it was not possible before, such as at archaeological sites [22], or in forestry [23] and agriculture [24]. In summary, traditional surveying only allows to collect discrete data of the feature lines that determine a surface, border, slope change, etc., while the massive capture methods based on photogrammetry allow to collect continuous points of the surfaces [25].…”

Advances in the Restoration of Buildings with LIDAR Technology and 3D Reconstruction: Forged and Vaults of the Refectory of Santo Domingo de Orihuela (16th Century)

“…On the other hand, SfM photogrammetry [27,28] is employed, with digital photography by taking photographs using a Canon EOS 600D SLR camera with a Canon EF-S 18-55mm standard lens. The photographs were processed using Photoscan software and metashape [29][30][31][32][33][34] (Figure 5 ). Data collection with the Laica Scan Station C10 Laser Scanner was carried out at different times, before the start of the works (2015) and after completion of the works (2019), choosing a position centred in the Refectory on a tripod, so that the scanning distances were, at most, of the order of 15 m. The intermediate state of the works was recorded with six locations on different dates (2018 and 2019) given that the demolition and reconstruction process took place in different phases, each one corresponding to each span (five arches and six vaults).…”

A Survey of Applications With Combined BIM and 3D Laser Scanning in the Life Cycle of Buildings

“…Manual process with software is conducted subsequently. Manual modeling method is adopted frequently for heritage buildings [35]- [37], which consist of heterogeneous, complex, and irregular components. There are currently no automatic software processes for the parametric design of the heritage buildings components.…”