VIRTUAL CAMPUS TOUR GENERATION USING UAV DATA: CASE STUDY GEBZE TECHNICAL UNIVERSITY

Abstract

In recent years, with the remarkable development in game engines, virtual reality (VR) technologies, which immerse users inside a synthetic environment, became very popular and were increasingly integrated into the visualisation of geospatial data. In the Covid-19 pandemic, restricting people's mobility, the interest in VR visits was rapidly increased. In the scope of a scientific research project, a three dimensional (3D) virtual tour for Gebze Technical University Campus was generated by integrating very high resolution unmanned air vehicle (UAV) data into a virtual environment utilizing Unity game engine. Regarding high geolocation accuracy and spatial resolution, low cost, short processing time, and 3D realistic model generation performance, UAV data is largely demanded in varied scientific and commercial applications. In this study, the campus area was collected with 2.18 cm ground sampling distance (GSD) from 80 m flight altitude using 20 MegaPixel UAV digital camera. The UAV data was processed by Agisoft Metashape, structure from motion (SFM) based image matching software, and then high-quality 3D textured models were generated. The aerial imagery was oriented by ground control points (GCPs), carefully distributed in the study area. The geometric accuracy of the image orientation was calculated as ±8 mm (?0.4 pixels). For virtual reality integration, first, the 3D textured models derived from UAV data were imported into the Unity game engine. After that, optimization techniques including occlusion culling, space subdivision were applied to the models to prevent problems that may arise due to transferring high poly models to game engines. Thus, objects and textures have been transferred with the highest resolution to achieve a realistic virtual experience. For creating a more detailed and realistic environment, 3D models of trees, lighting poles, benches, arbours, and information panels were added to the model using available assets in Unity. Also, the metadata about buildings (e.g. building name, floor area and the number of staff) were added to the 3D building models. Finally, a player with a first-person camera is implemented for the virtual tour in the integrated 3D models. In this study, the encountered problems and recommended solutions for creating a virtual campus are presented. © 2022 Elsevier B.V., All rights reserved.