Planning tactical operations on topographic maps, for rescue or military missions, is a complex process conducted by interdisciplinary experts and involves the time-consuming derivation of 3D information from 2D maps, mostly solely executed by experienced professionals. Previous research repeatedly showed that virtual reality (VR) can convey spatial relationships and complex 3D structures intuitively. In this work, we leverage the benefits of immersive head-mounted displays (HMDs) and present the design, implementation, and evaluation of a collaborative VR application for tactical resource planning on spatial data. We derived system and design requirements from consultations with domain experts and observations of a military on-site staff exercise, a simulation-based training aiming to strengthen rapid decision-making and teamwork during a time of crisis. To evaluate our prototype, we conducted semi-structured interviews with domain experts who organized and observed field tests at different military staff exercises. The interviews support the proposed design of the prototype and show general design implications for planning tools in VR. Our results show that the potential of VR-based tactical resource planning is dependent on the technical features as well as on non-technical environmental aspects, such as user attitude, prior experience, and interoperability.

We present our approach for the immersive analysis of spatio-temporal data, using a three-dimensional virtual globe. We display quantitative data as country-shaped elevated polygons and animate elevation levels over time to represent the temporal dimension. This approach allows us to investigate global patterns of behaviour, like pandemic infection data. By using a virtual reality setting, we intend to increase our understanding of spatial data and potential global relationships. Based on the development of our prototype, we outline research challenges we see emerging in this context.

The 2022 VGTC Virtual Reality Best Dissertation Award goes to Nami Ogawa, a 2020 graduate from the University of Tokyo, for her dissertation entitled, “Effect of Self-Avatar Anthropomorphism on Perception and Behavior in Virtual Environments.”

For our society to be more inclusive and accessible, the more than 2.2 billion people worldwide with limited vision should be considered more frequently in design decisions, such as architectural planning. To help architects in evaluating their designs and give medical personnel some insight on how patients experience cataracts, we worked with ophthalmologists to develop the first medically-informed, pilot-studied simulation of cataracts in eye-tracked augmented reality (AR). To test our methodology and simulation, we conducted a pilot study with cataract patients between surgeries of their two cataract-affected eyes. Participants compared the vision of their corrected eye, viewing through simulated cataracts, to that of their still affected eye, viewing an unmodified AR view. In addition, we conducted remote experiments via video call, live adjusting our simulation and comparing it to related work, with participants who had cataract surgery a few months before. We present our findings and insights from these experiments and outline avenues for future work.

Abstract We propose a novel visualization technique for graphs that are attributed with scalar data. In many scenarios, these attributes (e.g., birth date in a family network) provide ambient context information for the graph structure, whose consideration is important for different visual graph analysis tasks. Graph attributes are usually conveyed using different visual representations (e.g., color, size, shape) or by reordering the graph structure according to the attribute domain (e.g., timelines). While visual encodings allow graphs to be arranged in a readable layout, assessingcontextualinformation such as the relative similarities of attributes across the graph is often cumbersome. In contrast, attribute‐based graph reordering serves the comparison task of attributes, but typically strongly impairs the readability of thestructuralinformation given by the graph's topology. In this work, we augment force‐directed node‐link diagrams with a continuous ambient representation of the attribute context. This way, we provide a consistent overview of the graph's topological structure as well as its attributes, supporting a wide range of graph‐related analysis tasks. We resort to an intuitive height field metaphor, illustrated by a topographic map rendering using contour lines and suitable color maps. Contour lines visually connect nodes of similar attribute values, and depict their relative arrangement within the global context. Moreover, our contextual representation supports visualizing attribute value ranges associated with graph nodes (e.g., lifespans in a family network) as trajectories routed through this height field. We discuss how user interaction with both the structural and the contextual information fosters exploratory graph analysis tasks. The effectiveness and versatility of our technique is confirmed in a user study and case studies from various application domains.

The perception of light is inherently different inside a virtual reality (VR) or augmented reality (AR) simulation when compared to the real world. Conventional head-worn displays (HWDs) are not able to display the same high dynamic range of brightness and color as the human eye can perceive in the real world. To mimic the perception of real-world scenes in virtual scenes, it is crucial to reproduce the effects of incident light on the human visual system. In order to advance virtual simulations towards perceptual realism, we present an eye-tracked VR/AR simulation comprising effects for gaze-dependent temporal eye adaption, perceptual glare, visual acuity reduction, and scotopic color vision. Our simulation is based on medical expert knowledge and medical studies of the healthy human eye. We conducted the first user study comparing the perception of light in a real-world low-light scene to a VR simulation. Our results show that the proposed combination of simulated visual effects is well received by users and also indicate that an individual adaptation is necessary, because perception of light is highly subjective.

Vision impairments, such as cataracts, affect the way many people interact with their environment, yet are rarely considered by architects and lighting designers because of a lack of design tools. To address this, we present a method to simulate vision impairments, in particular cataracts, graphically in virtual reality (VR), using eye tracking for gaze-dependent effects. We also conduct a VR user study to investigate the effects of lighting on visual perception for users with cataracts. In contrast to existing approaches, which mostly provide only simplified simulations and are primarily targeted at educational or demonstrative purposes, we account for the user's vision and the hardware constraints of the VR headset. This makes it possible to calibrate our cataract simulation to the same level of degraded vision for all participants. Our study results show that we are able to calibrate the vision of all our participants to a similar level of impairment, that maximum recognition distances for escape route signs with simulated cataracts are significantly smaller than without, and that luminaires visible in the field of view are perceived as especially disturbing due to the glare effects they create. In addition, the results show that our realistic simulation increases the understanding of how people with cataracts see and could therefore also be informative for health care personnel or relatives of cataract patients.

Real-time rendering of large point clouds requires acceleration structures that reduce the number of points drawn on screen. State-of-the art algorithms group and render points in hierarchically organized chunks with varying extent and density, which results in sudden changes of density from one level of detail to another, as well as noticeable popping artifacts when additional chunks are blended in or out. These popping artifacts are especially noticeable at lower levels of detail, and consequently in virtual reality, where high performance requirements impose a reduction in detail. We propose a continuous level-of-detail method that exhibits gradual rather than sudden changes in density. Our method continuously recreates a down-sampled vertex buffer from the full point cloud, based on camera orientation, position, and distance to the camera, in a point-wise rather than chunk-wise fashion and at speeds up to 17 million points per millisecond. As a result, additional details are blended in or out in a less noticeable and significantly less irritating manner as compared to the state of the art. The improved acceptance of our method was successfully evaluated in a user study.

In workplaces or publicly accessible buildings, escape routes are signposted according to official norms or international standards that specify distances, angles and areas of interest for the positioning of escape-route signs. In homes for the elderly, in which the residents commonly have degraded mobility and suffer from vision impairments caused by age or eye diseases, the specifications of current norms and standards may be insufficient. Quantifying the effect of symptoms of vision impairments like reduced visual acuity on recognition distances is challenging, as it is cumbersome to find a large number of user study participants who suffer from exactly the same form of vision impairments. Hence, we propose a new methodology for such user studies: By conducting a user study in virtual reality (VR), we are able to use participants with normal or corrected sight and simulate vision impairments graphically. The use of standardized medical eyesight tests in VR allows us to calibrate the visual acuity of all our participants to the same level, taking their respective visual acuity into account. Since we primarily focus on homes for the elderly, we accounted for their often limited mobility by implementing a wheelchair simulation for our VR application.