RESUMO
Recent advancements in virtual reality (VR) may help unlock the full potential offered by 3-D photorealistic models generated using state-of-the-art photogrammetric methods. Using VR to carry out analyses on photogrammetric models has the potential to assist the user in performing basic offline engineering inspection of digital twins-digitized representations of real-world objects and structures. However, for such benefits to materialize, it is necessary to create suitable interactive systems for working with photogrammetric models in VR. To this end, this article presents PhotoTwinVR-an immersive gesture-controlled system for manipulation and inspection of 3-D photogrammetric models of physical objects in VR. An observational study with three domain experts validates the feasibility of the system design for practical use-cases involving offline inspections of pipelines and other 3-D structures.