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Now showing 1 - 10 of 32
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    LoBSTr: Real-time Lower-body Pose Prediction from Sparse Upper-body Tracking Signals
    (The Eurographics Association and John Wiley & Sons Ltd., 2021) Yang, Dongseok; Kim, Doyeon; Lee, Sung-Hee; Mitra, Niloy and Viola, Ivan
    With the popularization of games and VR/AR devices, there is a growing need for capturing human motion with a sparse set of tracking data. In this paper, we introduce a deep neural network (DNN) based method for real-time prediction of the lowerbody pose only from the tracking signals of the upper-body joints. Specifically, our Gated Recurrent Unit (GRU)-based recurrent architecture predicts the lower-body pose and feet contact states from a past sequence of tracking signals of the head, hands, and pelvis. A major feature of our method is that the input signal is represented by the velocity of tracking signals. We show that the velocity representation better models the correlation between the upper-body and lower-body motions and increases the robustness against the diverse scales and proportions of the user body than position-orientation representations. In addition, to remove foot-skating and floating artifacts, our network predicts feet contact state, which is used to post-process the lower-body pose with inverse kinematics to preserve the contact. Our network is lightweight so as to run in real-time applications. We show the effectiveness of our method through several quantitative evaluations against other architectures and input representations with respect to wild tracking data obtained from commercial VR devices.
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    Immersive Analytics of Heterogeneous Biological Data Informed through Need-finding Interviews
    (The Eurographics Association, 2021) Ripken, Christine; Tusk, Sebastian; Tominski, Christian; Vrotsou, Katerina and Bernard, Jürgen
    The goal of this work is to improve existing biological analysis processes by means of immersive analytics. In a first step, we conducted need-finding interviews with 12 expert biologists to understand the limits of current practices and identify the requirements for an enhanced immersive analysis. Based on the gained insights, a novel immersive analytics solution is being developed that enables biologists to explore highly interrelated biological data, including genomes, transcriptomes, and phenomes. We use an abstract tabular representation of heterogeneous data projected onto a curved virtual wall. Several visual and interactive mechanisms are offered to allow biologists to get an overview of large data, to access details and additional information on the fly, to compare selected parts of the data, and to navigate up to about 5 million data values in real-time. Although a formal user evaluation is still pending, initial feedback indicates that our solution can be useful to expert biologists.
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    Mathematics Input for Educational Applications in Virtual Reality
    (The Eurographics Association, 2021) Sansonetti, Luigi; Chatain, Julia; Caldeira, Pedro; Fayolle, Violaine; Kapur, Manu; Sumner, Robert W.; Orlosky, Jason and Reiners, Dirk and Weyers, Benjamin
    Virtual Reality (VR) enables new ways of learning by providing an interactive environment to learn through failure and by allowing new interaction methods engaging the users' bodies. Literature from productive failure and embodied cognition shows that these two aspects are particularly important for mathematics education. However, very little research has been looking into how to input mathematical expressions in VR. This gap impairs the learning process as it prevents the learners from connecting the VR mathematical objects with their formal representations. In this paper, we bridge this gap by presenting two interaction techniques for mathematics input in VR: a Keyboard-like method and a Drag-and-drop method. We report the results of our quantitative user study in terms of usability, ease of learning, low overhead, task load, and motion sickness.
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    Immersive Geometry-based and Image-based Exploration of Cultural Heritage Models
    (The Eurographics Association, 2021) Farràs, Arnau; Comino Trinidad, Marc; Andujar, Carlos; Hulusic, Vedad and Chalmers, Alan
    Recent advances in 3D acquisition technologies have facilitated the inexpensive digitization of cultural heritage. In addition to the 3D digital model, in many cases multiple photo collections are also available. These photo collections often provide valuable information not included in the 3D digital model. In this paper we describe a VR-ready web application to simultaneously explore a cultural heritage model together with arbitrary photo collections. At any time, users can define a region of interest either explicitly or implicitly, and the application retrieves, scores, groups and shows a matching subset of the photos. Users can then select a photo to project it onto the 3D model, to inspect the photo separately, or to teleport to the position the photo was taken from. Unlike previous approaches for joint 2D-3D model exploration, our interface has been specifically adapted to VR. We conducted a user study and found that the application greatly facilitates navigation and provides a fast, intuitive access to the available photos. The application supports any modern browser running on desktop, mobile and VR headset systems.
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    Triggering the Past: Cultural Heritage Interpretation Using Augmented and Virtual Reality at a Living History Museum
    (The Eurographics Association, 2021) Shitut, Kunal; Geigel, Joe; Decker, Juilee; Jacobs, Gary; Doherty, Amanda; Hulusic, Vedad and Chalmers, Alan
    In this paper, we present a use case for the introduction of historical digital characters in the context of a living history museum. We describe a prototype system and framework that enables the use of augmented and virtual reality for placing a these characters in the museum space. The system uses a conversational interface for natural interaction, supports the scanning of objects in the museum space for guiding the conversation, and provides a common user experience on a variety of mixed reality devices including the Microsoft Hololens, mobile devices, and WebXR enabled Web browsers. We describe our character creation workflow, provide technical details on the implementation and discuss the user testing of the system. Findings from our testing suggest, that despite the analog, hands-on tradition of living history museums, the use of immersive technologies has the potential to greatly enhance the visitor experience while engaging users within the physical space of the museum.
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    SnakeBinning: Efficient Temporally Coherent Triangle Packing for Shading Streaming
    (The Eurographics Association and John Wiley & Sons Ltd., 2021) Hladky, Jozef; Seidel, Hans-Peter; Steinberger, Markus; Mitra, Niloy and Viola, Ivan
    Streaming rendering, e.g., rendering in the cloud and streaming via a mobile connection, suffers from increased latency and unreliable connections. High quality framerate upsampling can hide these issues, especially when capturing shading into an atlas and transmitting it alongside geometric information. The captured shading information must consider triangle footprints and temporal stability to ensure efficient video encoding. Previous approaches only consider either temporal stability or sample distributions, but none focuses on both. With SnakeBinning, we present an efficient triangle packing approach that adjusts sample distributions and caters for temporal coherence. Using a multi-dimensional binning approach, we enforce tight packing among triangles while creating optimal sample distributions. Our binning is built on top of hardware supported real-time rendering where bins are mapped to individual pixels in a virtual framebuffer. Fragment shader interlock and atomic operations enforce global ordering of triangles within each bin, and thus temporal coherence according to the primitive order is achieved. Resampling the bin distribution guarantees high occupancy among all bins and a dense atlas packing. Shading samples are directly captured into the atlas using a rasterization pass, adjusting samples for perspective effects and creating a tight packing. Comparison to previous atlas packing approaches shows that our approach is faster than previous work and achieves the best sample distributions while maintaining temporal coherence. In this way, SnakeBinning achieves the highest rendering quality under equal atlas memory requirements. At the same time, its temporal coherence ensures that we require equal or less bandwidth than previous state-of-the-art. As SnakeBinning outperforms previous approach in all relevant aspects, it is the preferred choice for texture-based streaming rendering.
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    Diegetic vs. Non-Diegetic GUIs: What do Virtual Reality Players Prefer?
    (The Eurographics Association, 2021) Saling, F.; Bernhardt, D.; Lysek, A.; Smekal, M.; Maiero, Jens and Weier, Martin and Zielasko, Daniel
    Graphical user interfaces should not be a limiting factor when it comes to designing immersive virtual reality games. In this work we evaluate two different GUI designs for VR games: A non-diegetic HUD and a diegetic GUI, utilizing objects in the virtual environment to convey information. A pilot study was conducted to measure the players presence in VR and their GUI preference. Our results indicate that players prefer the diegetic GUI over the non-diegetic one. However the results lack statistical significance and thus further studies are necessary to identify the factors leading to the this preference.
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    Aplicación del motor de videojuegos Unity para la reconstrucción virtual de yacimientos arqueológicos
    (The Eurographics Association, 2021) Calzado-Martínez, Alberto; García-Fernández, Ángel Luis; Ortega-Alvarado, Lidia M.; Ortega, Lidia M. and Chica, Antonio
    En este trabajo se presenta una aplicación desarrollada para enriquecer y ampliar las técnicas actuales de registro arqueológico. Basada en una arquitectura cliente-servidor, se ha utilizado el motor de videojuegos Unity para implementar una aplicación cliente sencilla e intuitiva que permite realizar la reconstrucción virtual de un yacimiento a partir del escaneado 3D in situ del terreno excavado, así como del escaneado 3D en laboratorio de los hallazgos más importantes. Así se consigue preservar la información espacial del yacimiento, y se facilita la visita virtual del mismo desde cualquier equipo conectado a Internet.
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    Augmented Reality for Web - A New Interaction Method Without Markers
    (The Eurographics Association, 2021) Silva, Luis F. A.; Silva, Frutuoso G. M.; Silva, F. and Gutierrez, D. and Rodríguez, J. and Figueiredo, M.
    In the new age of omnipresent internet, browsers are accessible on every device in everyday's life. Thus it is also needed new interaction methods to facilitate the interaction through browser. Augmented reality is one of the techniques that is available now via browser. In this paper we present a new method of interaction without physical markers for augmented reality via browser. The first part of the paper describes the use of augmented reality via browser using physical markers and its limitations. In the second part, we propose a solution to solve the limitations of augmented reality using physical markers, i.e. we propose a new interaction method to manipulate virtual objects without using physical markers. Finally, we show a simple augmented web game based on the new interaction method proposed.
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    Transfer-Function-Independent Acceleration Structure for Volume Rendering in Virtual Reality
    (The Eurographics Association, 2021) Faludi, Balázs; Zentai, Norbert; Zelechowski, Marek; Zam, Azhar; Rauter, Georg; Griessen, Mathias; Cattin, Philippe C.; Binder, Nikolaus and Ritschel, Tobias
    Visualizing volumetric medical datasets in a virtual reality environment enhances the sense of scale and has a wide range of applications in diagnostics, simulation, training, and surgical planning. To avoid motion sickness, rendering at the native refresh rate of the head-mounted display is important, and frame drops have to be avoided. Despite these strict requirements and the high computational complexity of direct volume rendering, it is feasible to provide a comfortable experience using volume ray casting on modern hardware. Many implementations use precomputed gradients or illumination to achieve the targeted frame rate, and most rely on acceleration structures, such as distance maps or octrees, to speed up the ray marching shader. With many of these techniques, the opacity of voxels is baked into the precomputed data, requiring a recomputation when the opacity changes. This makes it difficult to implement features that lead to a sudden change in voxel opacity, such as real-time transfer function editing, transparency masking, or toggling the visibility of segmented tissues. In this work, we present an empty space skipping technique using an octree that does not have to be recomputed when the transfer function is changed and performs well even when more complex transfer functions are used. We encode the content of the volume as bitfields in the octree and are able to skip empty areas, even with transfer functions that cannot efficiently be represented as a simple range of voxel values. We show that our approach allows arbitrarily editing of the transfer function in real-time while maintaining the target frame rate of 90 Hz.