From the Point Cloud to BIM Methodology for the Ideal Reconstruction of a Lost Bastion of the Cáceres Wall

Abstract

Thanks to the use of non-invasive techniques and remote sensing in a 19th century building, it was possible to demonstrate that said building is a lost part of the Cáceres wall. This wall was believed to maintain the straight line from a known section, but remote sensing makes it clear that at that point the wall makes a break creating a door of which there was no record. Once this premise was confirmed, an ideal reconstruction hypothesis was developed. For this, the work base was taken on the data collected in an exhaustive data collection process, which launched millions of control points and facilitated in theorizing the original state of this lost section. The HBIM methodology greatly facilitated the process, and will allow for possible modifications with an IFC file as advances are made in that area. Finally, the research proposes an architectural project path that takes into account the data obtained remotely, and that achieves the inclusion of this part of the city in cultural interest and, of course, in a protected and cataloged area.

Protocol Development for Point Clouds, Triangulated Meshes and Parametric Model Acquisition and Integration in an HBIM Workflow for Change Control and Management in a UNESCO’s World Heritage Site

“…The procedure followed within the research project [ 15 ] for data collection was based on a high-density sphere mesh separated by a maximum of 30 m (see Figure 7 a,b).…”

“…The second one was to mark the location of the targets using geopositioned steel tips to allow us to retake and expand these scans in the future and reference them into the main model; so, if in the future we had the possibility of accessing a property, we could go back to the physical mesh of steel spikes placed in the pavement to continue expanding our model obtained through TLS [27,33]. The procedure followed within the research project [15] for data collection was based on a high-density sphere mesh separated by a maximum of 30 m (see Figure 7a,b). The procedure followed within the research project [15] for data collection was based on a high-density sphere mesh separated by a maximum of 30 m (see Figure 7a,b).…”

“…The procedure followed within the research project [15] for data collection was based on a high-density sphere mesh separated by a maximum of 30 m (see Figure 7a,b). The procedure followed within the research project [15] for data collection was based on a high-density sphere mesh separated by a maximum of 30 m (see Figure 7a,b). The position of each sphere within the mesh was geolocated on the pavement using easily locatable topographic marking nails.…”

“…The incorporation of UAV systems in combination with SfM (Structure from Motion) methodologies has generated an immense capacity to study our buildings and historical sites as shown in recent studies [ 12 , 13 , 14 ]. What began as study tools for buildings and archaeological sites [ 15 , 16 ] nowadays has extended to historical urban areas, thanks to the equipment’s improvements (better and lighter cameras and better computers with more computing capacity) and to the powerful SfM process software tools in the field of analysis. Today, not only are we capable of analyzing a building but also a city.…”

“…Previously, the research team had already obtained important results in a nearby area in which it had located the remains of the Almohad Wall that were considered lost [ 8 , 15 , 24 ]. These remains of the Almohad Wall, which were considered missing and were poorly located in the official planimetry, were located, positioned and preserved through its inclusion in the city’s Preservation Plan.…”