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Now showing 1 - 10 of 46
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    Real-Time Rendering of Molecular Dynamics Simulation Data: A Tutorial
    (The Eurographics Association, 2017) Alharbi, Naif; Chavent, Matthieu; Laramee, Robert S.; Tao Ruan Wan and Franck Vidal
    Achieving real-time molecular dynamics rendering is a challenge, especially when the rendering requires intensive computation involving a large simulation data-set. The task becomes even more challenging when the size of the data is too large to fit into random access memory (RAM) and the final imagery depends on the input and output (I/O) performance. The large data size and the complex computation processing per frame pose a number of challenges. i.e. the I/O performance bottleneck, the computational processing performance costs, and the fast rendering challenge. Handling these challenges separately consumes a significant portion of the total processing time which may result in low frame rates. We address these challenges by proposing an approach utilizing advanced memory management and bridging the Open Computing Language (OpenCL) and Open Graphics Library (OpenGL) drivers to optimize the final rendering frame rate. We illustrate the concept of the memory mapping technique and the hybrid OpenCL and OpenGL combination through a real molecular dynamics simulation example. The simulation data-set specifies the evolution of 336,260 particles over 1981 time steps occupying 8 Gigabyte of memory. The dynamics of the system including the lipid-protein interactions can be rendered at up to 40 FPS.
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    User Interaction Feedback in a Hand-Controlled Interface for Robot Team Tele-operation Using Wearable Augmented Reality
    (The Eurographics Association, 2017) Cannavò, Alberto; Lamberti, Fabrizio; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    Continuous advancements in the field of robotics and its increasing spread across heterogeneous application scenarios make the development of ever more effective user interfaces for human-robot interaction (HRI) an extremely relevant research topic. In particular, Natural User Interfaces (NUIs), e.g., based on hand and body gestures, proved to be an interesting technology to be exploited for designing intuitive interaction paradigms in the field of HRI. However, the more sophisticated the HRI interfaces become, the more important is to provide users with an accurate feedback about the state of the robot as well as of the interface itself. In this work, an Augmented Reality (AR)-based interface is deployed on a head-mounted display to enable tele-operation of a remote robot team using hand movements and gestures. A user study is performed to assess the advantages of wearable AR compared to desktop-based AR in the execution of specific tasks.
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    Sketching for Real-time Control of Crowd Simulations
    (The Eurographics Association, 2017) Gonzalez, Luis Rene Montana; Maddock, Steve; Tao Ruan Wan and Franck Vidal
    Crowd simulations are used in various fields such as entertainment, training systems and city planning. However, controlling the behaviour of the pedestrians typically involves tuning of the system parameters through trial and error, a time-consuming process relying on knowledge of a potentially complex parameter set. This paper presents an interactive graphical approach to control the simulation by sketching in the simulation environment. The user is able to sketch obstacles to block pedestrians and lines to force pedestrians to follow a specific path, as well as define spawn and exit locations for pedestrians. The obstacles and lines modify the underlying navigation representation and pedestrian trajectories are recalculated in real time. The FLAMEGPU framework is used for the simulation and the game engine Unreal is used for visualisation. We demonstrate the effectiveness of the approach using a range of scenarios, producing interactive editing and frame rates for tens of thousands of pedestrians. A comparison with the commercial software MassMotion is also given.
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    Downsampling and Storage of Pre-Computed Gradients for Volume Rendering
    (The Eurographics Association, 2017) Díaz-García, Jesús; Brunet, Pere; Navazo, Isabel; Vázquez, Pere-Pau; Fco. Javier Melero and Nuria Pelechano
    The way in which gradients are computed in volume datasets influences both the quality of the shading and the performance obtained in rendering algorithms. In particular, the visualization of coarse datasets in multi-resolution representations is affected when gradients are evaluated on-the-fly in the shader code by accessing neighbouring positions. This is not only a costly computation that compromises the performance of the visualization process, but also one that provides gradients of low quality that do not resemble the originals as much as desired because of the new topology of downsampled datasets. An obvious solution is to pre-compute the gradients and store them. Unfortunately, this originates two problems: First, the downsampling process, that is also prone to generate artifacts. Second, the limited bit size of storage itself causes the gradients to loss precision. In order to solve these issues, we propose a downsampling filter for pre-computed gradients that provides improved gradients that better match the originals such that the aforementioned artifacts disappear. Secondly, to address the storage problem, we present a method for the efficient storage of gradient directions that is able to minimize the minimum angle achieved among all representable vectors in a space of 3 bytes. We also provide several examples that show the advantages of the proposed approaches.
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    A 3 Cent Recognizer: Simple and Effective Retrieval and Classification of Mid-air Gestures from Single 3D Traces
    (The Eurographics Association, 2017) Caputo, Fabio Marco; Prebianca, Pietro; Carcangiu, Alessandro; Spano, Lucio D.; Giachetti, Andrea; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    In this paper we present a simple 3D gesture recognizer based on trajectory matching, showing its good performances in classification and retrieval of command gestures based on single hand trajectories. We demonstrate that further simplifications in porting the classic "1 dollar" algorithm approach from the 2D to the 3D gesture recognition and retrieval problems can result in very high classification accuracy and retrieval scores even on datasets with a large number of different gestures executed by different users. Furthermore, recognition can be good even with heavily subsampled path traces and with incomplete gestures.
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    12DoF Interaction for Scientific Visualisation
    (The Eurographics Association, 2017) Turner, Martin J.; Morris, Tim; Sandoval, Mario; Tao Ruan Wan and Franck Vidal
    This short extended abstract investigates human-computer interactions in relation to a specific Six Degree of Freedom (6DoF) input device; described is the driver development and calibration required for a novel piece of hardware; and after initial user tests and a questionnaire of satisfaction, we consider areas for further research. This abstract concludes with a discussion of the design and use of dual-6DoF input devices and from feedback how new interaction modes will be exploited.
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    3D Reconstruction of Facade and the Statues of the Church ''Maria Santissima dell'Elemosina'' in Biancavilla
    (The Eurographics Association, 2017) Tomasello, Simone Federico; Pazzi, Miriam Caterina; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    3D modelling plays a key role in the reconstruction of cultural heritage assets. It allows to give an idea of the original condition of a cultural heritage before time and weathering effects. This paper presents the 3D reconstruction of the church ''Maria Santissima dell'Elemosina'' through various software for modelling, as well as the acquisition and processing of elements. High resolution photos has been employed for faithful reproduction of the models details.
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    Perimeter Detection in Sketched Drawings of Polyhedral Shapes
    (The Eurographics Association, 2017) Company, Pedro; Varley, Peter A. C.; Plumed, Raquel; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    This paper describes a new "envelope" approach for detecting object perimeters in line-drawings vectorised from sketches of polyhedral objects. Existing approaches for extracting contours from digital images are unsuitable for Sketch-Based Modelling, as they calculate where the contour is, but not which elements of the line-drawing belong to it. In our approach, the perimeter is described in terms of lines and junctions (including intersections and T-junctions) of the original line drawing.
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    Procedural Generation of Natural Environments with Restrictions
    (The Eurographics Association, 2017) Gasch, Cristina; Chover, Miguel; Remolar, Inmaculada; Fco. Javier Melero and Nuria Pelechano
    Natural environments are a very important part of virtual worlds, both for video games and for simulators, but their manual creation can be a very expensive job. The procedural creation of these, allows to generate them easily and quickly, although there is no way to control the final result quickly and accurately. The purpose of this work is to present a new method of creation, that allows the procedural generation of a natural environment for applications such as rail shooter. The vegetation of the natural environment will be placed automatically along the area of the route. The method presented, is based on establishing on the ground a grid of points which are assigned a random function of probability of appearance of each species based on Perlin noise. In addition, the method draws from the heightmap the values necessary to distribute the natural elements. These values are combined along the distance of the route and next to a noise distribution, thus obtaining placement patterns that have a greater probability of occurrence in favorable points of the map and near the route. The results show that the method allows the procedural generation of these environments for any heightmap, also focusing the realism and the placement of the natural elements in the user visualization zone.
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    Time-oriented Cartographic Treemaps for Visualization of Public Healthcare Data
    (The Eurographics Association, 2017) Tong, Chao; McNabb, Liam; Laramee, Robert S.; Lyons, Jane; Walters, Angharad; Berridge, Damon; Thayer, Daniel; Tao Ruan Wan and Franck Vidal
    Cartographic treemaps offer a way to explore and present hierarchical multi-variate data that combines the space-efficient advantages of treemaps for the display of hierarchical data together with relative geo-spatial location from maps in the form of a modified cartogram. They offer users a space-efficient overview of the complex, multi-variate data coupled with the relative geo-spatial location to enable and facilitate exploration, analysis, and comparison. In this paper, we introduce time as an additional variate, in order to develop time-oriented cartographic treemaps. We design, implement and compare a range of visual layout options highlighting advantages and disadvantage of each. We apply the method to the study of UK-centric electronic health records data as a case study. We use the results to explore the trends of a range of health diagnoses in each UK healthcare region over multiple years exploiting both static and animated visual designs. We provide several examples and user options to evaluate the performance in exploration, analysis, and comparison. We also report the reaction of domain experts from health science.