Context 168 - June 2021

22 C O N T E X T 1 6 8 : J U N E 2 0 2 1 to a million times a second, reflecting back to the laser scanner, which computes its distance to the scanned surface. These coordinates, or points, come together to create a point cloud, accurately defining the surface geometry with up to millimetre accuracy. Scans are then taken from multiple positions with enough overlap to allow them to be joined together, creating a point cloud with complete coverage of both the interior and exterior of the site. For this project, we used the terrestrial 3D laser scanner Z+F Imager. This scanner has the ability to record HDR colour information to layer on the point cloud. The box allowed us to scan from unique vantage points of the exterior, including providing excellent coverage of the roof.What was also novel for us in the workflow at the Hill House was the addition of a thermal camera attached to the scanner, which allowed us to record a 360-degree panorama of infrared information and apply it to the point cloud. Recording thermal data in 3D space allows us to visualise how damp could be moving throughout the house with a more holistic point of view. By being able to directly visualise how the damp from the chimney, for example, speaks to a patch of damp in the corner of a room seems simple enough, but when visualised together is incredibly powerful in communicating how the house functions as a single unit. Once a second comparative survey is completed in the coming months, the data can be taken forward to inform conservation, interpretation and site management decisions. The plan is to return to the house in 2021 for the next round of survey, so that we can assess how the box has affected the damp ingress of the house. We are still very much in the midst of this project. We have produced a baseline dataset, documenting how the house was faring in the summers of 2018 and 2019, With this baseline, we can create visualisations, and provide vir- tual accessibility and education about the house. Behind the scenes, it has allowed us the oppor- tunity to collaborate with novel and innovative workflows of documentation and investigation, which can be applied to all the sites we care for and document. Through the combination of techniques and disciplines, we are uncovering new ways to tell the stories of our heritage. At the Hill House, the newly appointed research and development team, led by LDN Architects, will begin to dig deeper into this information over the coming months to help shape our long-term approach of conserving this vital piece of Scottish heritage. Sophia Mirashrafi is a project officer on the digital innovation team and Maureen Young a conservation scientist on the science team, both at Historic Environment Scotland. A 3D model generated from laser scans of the exterior of the Hill House A view of 2019 thermal point cloud data of the south elevation

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