Performing submarine field survey without scuba gear using GIS-like mapping in a Virtual Reality environment

Geomorphological and geological studies of the seafloor benefit today from both ROV exploration and from acquisition of high resolution bathymetric data. Although both represent significant improvements to study submarine domains, the understanding of the studied objects is made more difficult than on land given the limited visual perception provided by the ROV camera due to the attenuation of light in the water and the need to use artificial illumination. Likewise, mapping can be performed using GIS software for digital elevation models and its derivatives (e.g. slope or shade raster), mostly in a 2D map view only. So, the submarine studies lack the field survey stage performed in classical onshore works that allows clear visualization and appreciation of the studied objects. Our aim is to develop a solution allowing the visualization of Digital Elevation Models (DEM) and 3D models derived from Structure-from-Motion (SfM) within a virtual reality environment, and to use these data for geomorphological and geological analysis. For this, we use an Oculus Rift headset, Touch controllers, and the Unity game engine, with GIS-like interaction capabilities. The free and open Unity package that we are developing allows, at this stage, data visualization and working at a 1:1 scale in a georeferenced system. The user can therefore move freely within a 3D immersive environment that includes custom topographic data. For quantitative observations, we develop tools (ruler, compass) allowing measurements similar to those performed during geomorphological or geological field work. We also add the possibility to map objects. Digitizing in 3D is achieved with a laser pointed towards the data, providing great precision. The user can thus create pseudo shapefiles using the same three graphic primitives, and that are compatible with standard GIS software. Beside these functionalities, we also implement a spatial user interface displaying help and information and a teleportation tool preventing motion sickness. The users that have tested this solution are enthusiastic and agree that it helps to better appreciate and understand the shape and geometry of the studied objects. It was also used to present and explain 3D models of outcrops to master students. Further developments will port the solution for other headsets, facilitate the data import (e.g., standard file formats for 3D objects and DEMs), create and manage of multiple layers of shapefiles, and include multiplayer online gaming capabilities to allow remote co-working with colleague(s) at other distant locations, or a whole classroom.