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Now showing 1 - 10 of 56
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    Challenges in the Digitisation of a High-reflective Artwork
    (The Eurographics Association, 2021) Catalano, Chiara Eva; Brunetto, Erika; Mortara, Michela; Pizzi, Corrado; Hulusic, Vedad and Chalmers, Alan
    In this paper we report about the photogrammetric acquisition and reconstruction of a contemporary artwork, performed by offthe- shelf software. The ceramic piece of art is "Il Libro d'Oro del Terzo Paradiso" ("The Golden Book of the Third Paradise") by Michelangelo Pistoletto, accessed and studied in the framework of a regional project. This artefact is particularly challenging. On the one hand, it is golden coated and, as such, highly reflective. Hence, images are likely to suffer from highlight spots, shadows or self-reflections, and the reconstructed point cloud is typically noisy. On the other hand, the object exhibits simple geometry, mainly composed of planar surfaces, and is highly symmetric; however, it possesses detail features and undercuts. The symmetric nature of the object and reflections misled the image alignment, and the noise in the data turned out to be of the same scale as the detail features. We will discuss all the steps of the process, aimed at obtaining a high quality and accurate 3D model using low-cost tools.
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    Virtual Dance Museum: the Case of Greek/Cypriot Folk Dancing
    (The Eurographics Association, 2021) Aristidou, Andreas; Andreou, Nefeli; Charalambous, Loukas; Yiannakidis, Anastasios; Chrysanthou, Yiorgos; Hulusic, Vedad and Chalmers, Alan
    In this paper, we have designed and developed a virtual dance museum to provide the technological tools that allow for widely educating the public, most specifically the youngest generations, about the story, costumes, music, and history of our dances. The holistic documentation of our intangible cultural heritage creations is a critical necessity for the preservation and the continuity of our identity as Europeans. In that direction, we have employed a specially designed relational database schema that holistically structures the information within the database, and is ideal for archiving, presenting, further analyzing, and re-using dance motion data. Data have been retargeted to a virtual character, dressed with traditional uniform and simulated to achieve realism. The users can view and interact with the archived data using advanced 3D character visualization in three ways: via an online 3D virtual environment; in virtual reality using headset; and in augmented reality, where the 3D characters can co-inhabit the real world. Our museum is publicly accessible, and also enables motion data reusability, facilitating dance learning applications through gamification.
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    Implicit Modeling of Patient-Specific Aortic Dissections with Elliptic Fourier Descriptors
    (The Eurographics Association and John Wiley & Sons Ltd., 2021) Mistelbauer, Gabriel; Rössl, Christian; Bäumler, Kathrin; Preim, Bernhard; Fleischmann, Dominik; Borgo, Rita and Marai, G. Elisabeta and Landesberger, Tatiana von
    Aortic dissection is a life-threatening vascular disease characterized by abrupt formation of a new flow channel (false lumen) within the aortic wall. Survivors of the acute phase remain at high risk for late complications, such as aneurysm formation, rupture, and death. Morphologic features of aortic dissection determine not only treatment strategies in the acute phase (surgical vs. endovascular vs. medical), but also modulate the hemodynamics in the false lumen, ultimately responsible for late complications. Accurate description of the true and false lumen, any communications across the dissection membrane separating the two lumina, and blood supply from each lumen to aortic branch vessels is critical for risk prediction. Patient-specific surface representations are also a prerequisite for hemodynamic simulations, but currently require time-consuming manual segmentation of CT data. We present an aortic dissection cross-sectional model that captures the varying aortic anatomy, allowing for reliable measurements and creation of high-quality surface representations. In contrast to the traditional spline-based cross-sectional model, we employ elliptic Fourier descriptors, which allows users to control the accuracy of the cross-sectional contour of a flow channel. We demonstrate (i) how our approach can solve the requirements for generating surface and wall representations of the flow channels, (ii) how any number of communications between flow channels can be specified in a consistent manner, and (iii) how well branches connected to the respective flow channels are handled. Finally, we discuss how our approach is a step forward to an automated generation of surface models for aortic dissections from raw 3D imaging segmentation masks.
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    Interactive 3D Artefact Puzzles to Support Engagement Beyond the Museum Environment
    (The Eurographics Association, 2021) Rodriguez Echavarria, Karina; Samaroudi, Myrsini; LLoyd, Jack; Weyrich, Tim; Hulusic, Vedad and Chalmers, Alan
    The need for online 3D interactive experiences was evidenced during the COVID-19 lockdowns, as audiences across the world have been unable to visit museums, physically interact with their collections on site or digitally interact with technologies and digital media situated within such settings. As a response, this research addresses gaps identified in a review of the digital offerings from UK and US museums during the 2020 lockdowns, highlighting the limited number and nature of 3D interactive offerings provided, despite the wide efforts on 3D digitisation over the last decade. Thus, the research investigates the development and testing of an online 3D interactive activity, resembling a physical activity situated in the archaeological gallery of Brighton Museum and Art Gallery (UK). Through a pilot user survey, the research aims to understand what is the impact of such online offerings to better contextualise heritage collections; enhance cultural heritage learning and appreciation; and complement physical activities of similar nature. The analysis of audiences’' opinions about these interactions can be of great importance, as such activities have the power to enable active access to cultural heritage resources regardless of the physical location of users and transform heritage experiences in the long term. Our research indicates that, while the physical experience might offer advantages as far as it concerns the familiarity with the tactile nature of interaction, the digital counterpart has potential to allow for the experience of assembling the puzzle to achieve a wider reach.
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    Strategies for Generating Multi-Time Frame Localization of Cardiac MRI
    (The Eurographics Association, 2021) Sabokrohiyeh, Samin; Ang, Kathleen; Samavati, Faramarz; Oeltze-Jafra, Steffen and Smit, Noeska N. and Sommer, Björn and Nieselt, Kay and Schultz, Thomas
    4D Flow MRI is a recent promising technology that is able to capture blood flow information within the heart chambers over a cardiac cycle. To accurately study the flow inside the chambers, there is a need for a high quality anatomical reference which can be provided by another scan known as 3D cine MRI (short-axis 3D (multiple 2D slices) cine SSFP). To take advantage of both scans, data fusion can be done using an intensity-based registration. To reduce the impact of noise on the registration result and the chance of misalignment between the organs, defining a region of interest (localization) should be done prior to the registration. Localizing a dataset - especially a time-varying dataset - can be a daunting task since the localization should be provided for all time frames. We design and evaluate different strategies for extending single time frame localization to time varying data in order to register the 4D Flow MRI and 3D cine MRI over the cardiac cycle.
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    Film Directing for Computer Games and Animation
    (The Eurographics Association and John Wiley & Sons Ltd., 2021) Ronfard, Rémi; Bühler, Katja and Rushmeier, Holly
    Over the last forty years, researchers in computer graphics have proposed a large variety of theoretical models and computer implementations of a virtual film director, capable of creating movies from minimal input such as a screenplay or storyboard. The underlying film directing techniques are also in high demand to assist and automate the generation of movies in computer games and animation. The goal of this survey is to characterize the spectrum of applications that require film directing, to present a historical and up-to-date summary of research in algorithmic film directing, and to identify promising avenues and hot topics for future research.
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    SHREC 2021: Surface-based Protein Domains Retrieval
    (The Eurographics Association, 2021) Langenfeld, Florent; Aderinwale, Tunde; Christoffer, Charles; Shin, Woong-Hee; Terashi, Genki; Wang, Xiao; Kihara, Daisuke; Benhabiles, Halim; Hammoudi, Karim; Cabani, Adnane; Windal, Feryal; Melkemi, Mahmoud; Otu, Ekpo; Zwiggelaar, Reyer; Hunter, David; Liu, Yonghuai; Sirugue, Léa; Nguyen, Huu-Nghia H.; Nguyen, Tuan-Duy H.; Nguyen–Truong, Vinh-Thuyen; Le, Danh; Nguyen, Hai-Dang; Tran, Minh-Triet; Montès, Matthieu; Biasotti, Silvia and Dyke, Roberto M. and Lai, Yukun and Rosin, Paul L. and Veltkamp, Remco C.
    Proteins are essential to nearly all cellular mechanism, and often interact through their surface with other cell molecules, such as proteins and ligands. The evolution generates plenty of different proteins, with unique abilities, but also proteins with related functions hence surface, which is therefore of primary importance for their activity. In the present work, we assess the ability of five methods to retrieve similar protein surfaces, using either their shape only (3D meshes), or their shape and the electrostatic potential at their surface, an important surface property. Five different groups participated in this challenge using the shape only, and one group extended its pre-existing algorithm to handle the electrostatic potential. The results reveal both the ability of the methods to detect related proteins and their difficulties to distinguish between topologically related proteins.
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    Cloud-Assisted Hybrid Rendering for Thin-Client Games and VR Applications
    (The Eurographics Association, 2021) Tan, Yu Wei; Kim-Chan, Louiz; Halim, Anthony; Bhojan, Anand; Lee, Sung-Hee and Zollmann, Stefanie and Okabe, Makoto and Wünsche, Burkhard
    We introduce a novel distributed rendering approach to generate high-quality graphics in thin-client games and VR applications. Many mobile devices have limited computational power to achieve ray tracing in real-time. Hence, hardware-accelerated cloud servers can perform ray tracing instead and have their output streamed to clients in remote rendering. Applying the approach of distributed hybrid rendering, we leverage the computational capabilities of both the thin client and powerful server by performing rasterization locally while offloading ray tracing to the server. With advancements in 5G technology, the server and client can communicate effectively over the network and work together to produce a high-quality output while maintaining interactive frame rates. Our approach can achieve better visuals as compared to local rendering but faster performance as compared to remote rendering.
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    Projection Mapping for In-Situ Surgery Planning by the Example of DIEP Flap Breast Reconstruction
    (The Eurographics Association, 2021) Martschinke, Jana; Klein, Vanessa; Kurth, Philipp; Engel, Klaus; Ludolph, Ingo; Hauck, Theresa; Horch, Raymund; Stamminger, Marc; Oeltze-Jafra, Steffen and Smit, Noeska N. and Sommer, Björn and Nieselt, Kay and Schultz, Thomas
    Nowadays, many surgical procedures require preoperative planning, mostly relying on data from 3D imaging techniques like computed tomography or magnetic resonance imaging. However, preoperative assessment of this data is carried out on the PC (using classical CT/MR viewing software) and not on the patient's body itself. Therefore, surgeons need to transfer both their overall understanding of the patient's individual anatomy and also specific markers and labels for important points from the PC to the patient only with the help of imaginative power or approximative measurement. In order to close the gap between preoperative planning on the PC and surgery on the patient, we propose a system to directly project preoperative knowledge to the body surface by projection mapping. As a result, we are able to display both assigned labels and a volumetric and view-dependent view of the 3D data in-situ. Furthermore, we offer a method to interactively navigate through the data and add 3D markers directly in the projected volumetric view. We demonstrate the benefits of our approach using DIEP flap breast reconstruction as an example. By means of a small pilot study, we show that our method outperforms standard surgical planning in accuracy and can easily be understood and utilized even by persons without any medical knowledge.
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    SimJEB: Simulated Jet Engine Bracket Dataset
    (The Eurographics Association and John Wiley & Sons Ltd., 2021) Whalen, Eamon; Beyene, Azariah; Mueller, Caitlin; Digne, Julie and Crane, Keenan
    This paper introduces the Simulated Jet Engine Bracket Dataset (SimJEB) [WBM21]: a new, public collection of crowdsourced mechanical brackets and accompanying structural simulations. SimJEB is applicable to a wide range of geometry processing tasks; the complexity of the shapes in SimJEB offer a challenge to automated geometry cleaning and meshing, while categorical labels and structural simulations facilitate classification and regression (i.e. engineering surrogate modeling). In contrast to existing shape collections, SimJEB's models are all designed for the same engineering function and thus have consistent structural loads and support conditions. On the other hand, SimJEB models are more complex, diverse, and realistic than the synthetically generated datasets commonly used in parametric surrogate model evaluation. The designs in SimJEB were derived from submissions to the GrabCAD Jet Engine Bracket Challenge: an open engineering design competition with over 700 hand-designed CAD entries from 320 designers representing 56 countries. Each model has been cleaned, categorized, meshed, and simulated with finite element analysis according to the original competition specifications. The result is a collection of 381 diverse, high-quality and application-focused designs for advancing geometric deep learning, engineering surrogate modeling, automated cleaning and related geometry processing tasks.