COMMUNICATE YOUR GEOSCIENCE WITH SMARTPHONE-BASED VIRTUAL REALITY

Creating high-resolution Digital Surface Models (DSM) has become an essential tool for modern field geologists. Such 3D models show widespread applications across the geosciences, such as the investigation of geomorphological processes, the characterization of inaccessible geological structures, geohazard assessments, etc. Conventional methods for data acquisition consist of (i) laser-based (LIDAR/TLS) techniques and (ii) photogrammetry using photographs captured from Unmanned Aerial Vehicle (UAV) and/or combined to field digital camera. The latter has considerably grown in the last decade due to its low-cost implementation and the rise of many affordable software packages producing DSM (e.g., Agisoft Photoscan, MicMac, VisualSFM). Even if such models are easy to acquire, taking full advantage of 3D rendering during data presentation may be more complicated. This is where Virtual Reality (VR) systems step in aiming as being used as supporting tool for scientific presentations. Indeed, VR headsets such as Google Cardboard - or more sophisticated ones - create an immersive virtual field experience by which realistic geology outcrop and/or post-processed 3D models can be displayed and explored.

We built such DSM for several cases study illustrating multiple field scales: (i) large-scale open-pit mine (Lessines, SW Belgium), (ii) medium-scale Rochefort Cave Laboratory (SE Belgium), (iii) the Luzéronde Sand Dune (West of the Noirmoutier island, France) as well as (iv) oriented hand-samples. The main goals of these projects were to better constrain the orientation of inaccessible geological (e.g. faults, tectonic, gravitational and cooling joints, and sediments bedding) and geomorphological structures (e.g. coastal morphology, spatial and temporal erosional rate), to compare them to structural data surveyed on the field and in fine, to go through lithological and structural interpretations using both geometric and colorimetric/spectral clustering of DSM polygons. We thus present here general procedures and guidelines in order to help field geoscientists to create their own 3D digital models from the field up to its integration in a virtual world using Unity software framework and a smartphone-based VR headset.