Generating 3D CAD Models from Laser Scanning Point Cloud Data to Monitor and Preserve Heritage Buildings

Abstract

Condition monitoring of buildings can benefit from 3D laser scanning since the geometry of the building and some key features and components can be iden-tified for the purpose of retrofitting, cataloguing, or fully or partially reconstructing the building. The 3D reconstruction of heritage buildings, sites, and artefacts should be accurately performed so that their current state of conservation is conveniently studied to support imminent or future conservation actions. Point clouds, as the raw data from 3D laser scanning, enable a general visual representation but cannot distinguish between detailed components and substructures in a true 3D CAD model. Hence, to achieve a 3D CAD model from point clouds, manual or semi-automated techniques will be needed. This chapter discusses and evaluates point cloud-based modelling approaches that can be adopted in historic buildings and sites to construct their 3D CAD model with geometrical alterations, also known as an as-built 3D heritage model. To do this, a case study of a particular historic building called Ye Olde Trip to Jerusalem, in the city of Nottingham (the United Kingdom), is addressed, which is claimed to be the oldest pub in England (1189 AD). Being a reliable source of geometrical data to constitute Historic Building Information Models (HBIM), as-built 3D heritage models should be considered a prerequisite for non-destructive monitoring strategy to retrofit and maintain building components. Moreover, they are useful to produce immersive experiences to explore and disseminate heritage assets.