1,974 research outputs found

    Enabling collaboration in virtual reality navigators

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    In this paper we characterize a feature superset for Collaborative Virtual Reality Environments (CVRE), and derive a component framework to transform stand-alone VR navigators into full-fledged multithreaded collaborative environments. The contributions of our approach rely on a cost-effective and extensible technique for loading software components into separate POSIX threads for rendering, user interaction and network communications, and adding a top layer for managing session collaboration. The framework recasts a VR navigator under a distributed peer-to-peer topology for scene and object sharing, using callback hooks for broadcasting remote events and multicamera perspective sharing with avatar interaction. We validate the framework by applying it to our own ALICE VR Navigator. Experimental results show that our approach has good performance in the collaborative inspection of complex models.Postprint (published version

    Augmented Reality for Restoration/Reconstruction of Artefacts with Artistic or Historical Value

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    The artistic or historical value of a structure, such as a monument, a mosaic, a painting or, generally speaking, an artefact, arises from the novelty and the development it represents in a certain field and in a certain time of the human activity. The more faithfully the structure preserves its original status, the greater its artistic and historical value is. For this reason it is fundamental to preserve its original condition, maintaining it as genuine as possible over the time. Nevertheless the preservation of a structure cannot be always possible (for traumatic events as wars can occur), or has not always been realized, simply for negligence, incompetence, or even guilty unwillingness. So, unfortunately, nowadays the status of a not irrelevant number of such structures can range from bad to even catastrophic. In such a frame the current technology furnishes a fundamental help for reconstruction/restoration purposes, so to bring back a structure to its original historical value and condition. Among the modern facilities, new possibilities arise from the Augmented Reality (AR) tools, which combine the virtual reality (VR) settings with real physical materials and instruments. The idea is to realize a virtual reconstruction/restoration before materially acting on the structure itself. In this way main advantages are obtained among which: the manpower and machine power are utilized only in the last phase of the reconstruction; potential damages/abrasions of some parts of the structure are avoided during the cataloguing phase; it is possible to precisely define the forms and dimensions of the eventually missing pieces, etc. Actually the virtual reconstruction/restoration can be even improved taking advantages of the AR, which furnish lots of added informative parameters, which can be even fundamental under specific circumstances. So we want here detail the AR application to restore and reconstruct the structures with artistic and/or historical valu

    Abstract Data Visualisation in Mobile VR Platforms

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    Data visualisation, as a key tool in data understanding, is widely used in science and everyday life. In order data visualisation to be effective, perceptual factors and the characteristics of the display interface play a crucial role. Virtual Reality is nowadays accepted as a valid medium for scientific visualisation, because of its inherent characteristics of real-world emulation and intuitive interaction. However, the use of VR in abstract data visualisation is still limited. In this research, I investigate the use and suitability of mobile phone-based Virtual Reality as a medium for abstract data visualisation. I develop a prototype VR Android application and visualise data using the Scatterplot and Parallel Coordinates methods. After that, I conduct a user study to compare the effectiveness of the mobile VR application compared to a similar screen-based one by implementing some data exploration scenarios. The study results, while not being statistically significant, show improved accuracy and speed in the mobile VR visualisation application. The main conclusions are two-fold: Virtual Reality is beneficial for abstract data visualisation, even in the case of limited processing power and display resolution. Mobile VR, an affordable alternative to expensive desktop VR set-ups can be utilized as a data visualisation platform

    A method for viewing and interacting with medical volumes in virtual reality

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    The medical field has long benefited from advancements in diagnostic imaging technology. Medical images created through methods such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) are used by medical professionals to non-intrusively peer into the body to make decisions about surgeries. Over time, the viewing medium of medical images has evolved from X-ray film negatives to stereoscopic 3D displays, with each new development enhancing the viewer’s ability to discern detail or decreasing the time needed to produce and render a body scan. Though doctors and surgeons are trained to view medical images in 2D, some are choosing to view body scans in 3D through volume rendering. While traditional 2D displays can be used to display 3D data, a viewing method that incorporates depth would convey more information to the viewer. One device that has shown promise in medical image viewing applications is the Virtual Reality Head Mounted Display (VR HMD). VR HMDs have recently increased in popularity, with several commodity devices being released within the last few years. The Oculus Rift, HTC Vive, and Windows Mixed Reality HMDs like the Samsung Odyssey offer higher resolution screens, more accurate motion tracking, and lower prices than earlier HMDs. They also include motion-tracked handheld controllers meant for navigation and interaction in video games. Because of their popularity and low cost, medical volume viewing software that is compatible with these headsets would be accessible to a wide audience. However, the introduction of VR to medical volume rendering presents difficulties in implementing consistent user interactions and ensuring performance. Though all three headsets require unique driver software, they are compatible with OpenVR, a middleware that standardizes communication between the HMD, the HMD’s controllers, and VR software. However, the controllers included with the HMDs each has a slightly different control layout. Furthermore, buttons, triggers, touchpads, and joysticks that share the same hand position between devices do not report values to OpenVR in the same way. Implementing volume rendering functions like clipping and tissue density windowing on VR controllers could improve the user’s experience over mouse-and-keyboard schemes through the use of tracked hand and finger movements. To create a control scheme that is compatible with multiple HMD’s A way of mapping controls differently depending on the device was developed. Additionally, volume rendering is a computationally intensive process, and even more so when rendering for an HMD. By using techniques like GPU raytracing with modern GPUs, real-time framerates are achievable on desktop computers with traditional displays. However, the importance of achieving high framerates is even greater when viewing with a VR HMD due to its higher level of immersion. Because the 3D scene occupies most of the user’s field of view, low or choppy framerates contribute to feelings of motion sickness. This was mitigated through a decrease in volume rendering quality in situations where the framerate drops below acceptable levels. The volume rendering and VR interaction methods described in this thesis were demonstrated in an application developed for immersive viewing of medical volumes. This application places the user and a medical volume in a 3D VR environment, allowing the user to manually place clipping planes, adjust the tissue density window, and move the volume to achieve different viewing angles with handheld motion tracked controllers. The result shows that GPU raytraced medical volumes can be viewed and interacted with in VR using commodity hardware, and that a control scheme can be mapped to allow the same functions on different HMD controllers despite differences in layout

    Toward future 'mixed reality' learning spaces for STEAM education

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    Digital technology is becoming more integrated and part of modern society. As this begins to happen, technologies including augmented reality, virtual reality, 3d printing and user supplied mobile devices (collectively referred to as mixed reality) are often being touted as likely to become more a part of the classroom and learning environment. In the discipline areas of STEAM education, experts are expected to be at the forefront of technology and how it might fit into their classroom. This is especially important because increasingly, educators are finding themselves surrounded by new learners that expect to be engaged with participatory, interactive, sensory-rich, experimental activities with greater opportunities for student input and creativity. This paper will explore learner and academic perspectives on mixed reality case studies in 3d spatial design (multimedia and architecture), paramedic science and information technology, through the use of existing data as well as additional one-on-one interviews around the use of mixed reality in the classroom. Results show that mixed reality can provide engagement, critical thinking and problem solving benefits for students in line with this new generation of learners, but also demonstrates that more work needs to be done to refine mixed reality solutions for the classroom

    Performance Factors in Neurosurgical Simulation and Augmented Reality Image Guidance

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    Virtual reality surgical simulators have seen widespread adoption in an effort to provide safe, cost-effective and realistic practice of surgical skills. However, the majority of these simulators focus on training low-level technical skills, providing only prototypical surgical cases. For many complex procedures, this approach is deficient in representing anatomical variations that present clinically, failing to challenge users’ higher-level cognitive skills important for navigation and targeting. Surgical simulators offer the means to not only simulate any case conceivable, but to test novel approaches and examine factors that influence performance. Unfortunately, there is a void in the literature surrounding these questions. This thesis was motivated by the need to expand the role of surgical simulators to provide users with clinically relevant scenarios and evaluate human performance in relation to image guidance technologies, patient-specific anatomy, and cognitive abilities. To this end, various tools and methodologies were developed to examine cognitive abilities and knowledge, simulate procedures, and guide complex interventions all within a neurosurgical context. The first chapter provides an introduction to the material. The second chapter describes the development and evaluation of a virtual anatomical training and examination tool. The results suggest that learning occurs and that spatial reasoning ability is an important performance predictor, but subordinate to anatomical knowledge. The third chapter outlines development of automation tools to enable efficient simulation studies and data management. In the fourth chapter, subjects perform abstract targeting tasks on ellipsoid targets with and without augmented reality guidance. While the guidance tool improved accuracy, performance with the tool was strongly tied to target depth estimation – an important consideration for implementation and training with similar guidance tools. In the fifth chapter, neurosurgically experienced subjects were recruited to perform simulated ventriculostomies. Results showed anatomical variations influence performance and could impact outcome. Augmented reality guidance showed no marked improvement in performance, but exhibited a mild learning curve, indicating that additional training may be warranted. The final chapter summarizes the work presented. Our results and novel evaluative methodologies lay the groundwork for further investigation into simulators as versatile research tools to explore performance factors in simulated surgical procedures
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