RAPID AND LOW-COST PHOTOGRAMMETRIC SURVEY OF HAZARDOUS SITES, FROM MEASUREMENTS TO VR DISSEMINATION

Abstract. In the field of geomatics, the development of 3D surveying techniques that can produce dense point clouds and high-resolution three-dimensional models has opened the possibility of using these techniques to generate digital replicas of a given asset to be used in contexts of cultural promotion or entertainment.

These non-traditional applications have been made easier by the spreading of low-cost but fast surveying techniques, allowing them to be used in contexts or projects with fewer resources. Close-range photogrammetry is nowadays the cheapest, most flexible, and fastest technique that can be used to produce high-resolution and high-quality digital copies of reality. In this paper, we present an application of the Ant3D multi-camera system, a novel photogrammetric device designed for the rapid 3D surveying of sites characterized by poor accessibility and narrow spaces. The paper describes the three-dimensional acquisition of underground tunnels in a hazardous abandoned mining site. The digitalisation work aims to create 3D models to be experienced safely in a virtual- or augmented- reality immersive navigation of the site for cultural promotion. A workflow is proposed to turn raw reality-based 3D models into refined and efficient 3D assets that can be exploited in a game engine. Applications for mobile devices, desktop, and VR headsets, using the produced 3D assets are described.