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Item Low-cost Experimental Setups for Mid-air 3D Reconstruction(The Eurographics Association, 2015) Dancu, Alexandru; Fratarcangeli, Marco; Fourgeaud, Mickaël; Franjcic, Zlatko; Chindea, Daniel; Fjeld, Morten; Andrea Giachetti and Silvia Biasotti and Marco TariniThe reconstruction of the physical environment using a depth sensor involves data-intensive computations which are difficult to implement on mobile systems (e.g., tracking and aligning the position of the sensor with the depth maps). In this paper, we present two practical experimental setups for scanning and reconstructing real objects employing low-price, off-the-shelf embedded components and open-source libraries. As a test case, we scan and reconstruct a 23 m high statue using an octocopter without employing external hardwareItem CLIKSA - An Application for Physics Education in Secondary School(The Eurographics Association, 2014) Marín-Lora, Carlos; García-Fernández, Ignacio; Adolfo Munoz and Pere-Pau VazquezIn this paper we present an application for teaching Physics courses in secondary education. It is a web application, based on HTML5 and on JavaScript. We rely on the graphical capabilities of this technology, including rendering on 2D canvas context and SVG rendering, and we develop a framework for simulating physics behavior. We review other applications with similar features, explaining the motivations of the current development. The system architecture and the software design are discussed and the simulation techniques are explained. We finish with a discussion on some possible examples of use for the application and on the future development plans.Item Towards a 3D GIS for Underground Infrastructure(The Eurographics Association, 2016) Soria, Gregorio; Ortega, Lidia; Feito, Francisco R.; Alejandro Garcia-Alonso and Belen MasiaThe use of advanced software tools for groundwater management is essential to carry out the management of these underground infrastructure. Tools capable of accomplishing these processes are the so-called 3D GIS. However, these systems are not widely implemented, mainly because of their complexity. In this paper we present the data model of an underground infrastructure for city sanitation management. It discusses the design of the database, the acquisition and processing of such information, as well as the visualization and interaction with the resulting model.Item An Application to Interact with 3D Models Reconstructed from Medical Images(The Eurographics Association, 2012) Paulano, F.; Pulido, R.; Jiménez, J. J.; Isabel Navazo and Gustavo PatowAlthough the reconstruction of 3D models from medical images is not an easy task, there are many algorithms to perform it. However, the reconstructed models are usually large, have a lot of outliers and have not a correct topology. For that reason, the algorithms used to interact with them must be fast and robust. In this paper, we present an application that enables the interaction with models reconstructed from medical images. The application uses Marching Cubes to generate triangle soups from the medical images. Then, the user can define models by selecting a set of triangles. Once the models have been defined, the application allows to interact with them. In addition, a detailed collision detection is calculated between the models in the scene in order not only to avoid that models in the scene collide, but also to determine which triangles are overlapping. In addition, the calculation of distances and nearest points provides visual aid when the user is interacting with the models.Item A Moving Least Squares Method for Implant Model Deformation in Computer Aided Orthopedic Surgery for Fractures of Lower Extremities(The Eurographics Association, 2021) Ramírez, Esmitt; Coto, Ernesto; Silva, F. and Gutierrez, D. and Rodríguez, J. and Figueiredo, M.Preoperative planning is an essential step before performing any surgical procedure. Computer Aided Orthopedic Surgery (CAOS) systems are extensively used for the planning of surgeries for fractures of lower extremities. These systems are input an X-Ray image and the planning can be digitally overlaid onto the image. The planning includes reassembling the fractured bone and possibly adding implants to reduce the fracture. In many cases, the implant does not fit perfectly in the patient's anatomy and it must be bended to adjust the implant to the bone. This paper presents a new method for the deformation of implants in CAOS systems, based on the Moving Least Squares (MLS) method for 2D images. Several improvements over the original MLS method are introduced to achieve visual results similar to the real procedure and make the deformation process easier and simpler for the surgeon. The improvements are explained in detail and all parameter values are provided. Over 100 clinical surgeries have been already planned successfully using a CAOS system that employs the proposed technique.Item A Digital Approach for the Study of Roman Signacula From Syracuse, Sicily(The Eurographics Association, 2017) Tanasi, Davide; Milotta, Filippo L. M.; Gradante, Ilenia; Stanco, Filippo; Kaplan, Howard; Andrea Giachetti and Paolo Pingi and Filippo StancoIn the last decade the epigraphists have grown a new interest in signacula, a class of artifacts for a long time neglected. This has brought numerous contributions devoted to the different regional contexts, along with reflections on methodological questions, not to mention the momentum towards the digitizing of a corpus which counts at least 3,500 pieces, confirming the great potential of these artifacts in providing information related not only to the economy and to the administration of the ''res'', both in public and private sphere, but also about the profile of the signacula holders. In this scenario, a specific research question has been inspired by the Sicilian seals - about 60 signacula and a dozen impressions left by seals on mortar in burial contexts: it is possible to identify unequivocally a signaculum through its impression? Given for granted that the use of 3D documentation will bring along effective results in terms of improved readability of signacula and seals, the aim of this contribute is to establish a protocol for a semi-automatic matching between 3D models of seals and 3D models of impressions. As part of a preliminary scanning campaign of Late Roman impressions on mortars and metal seals from the catacombs of Syracuse, two bronze metal seals were digitized with a NextEngine 3D triangulation laser scanner and subsequently 3D printed with liquid resin with a Formlabs Form 2 SLA high resolution printer. The casts obtained, were experimentally used to create a set of impressions on mortar using different degrees and angles of pressure, in order to create similar but still different stamps. During the next step, the impressions were 3D scanned and used as ground truth for the outlined semi-automatic procedure of matching with the seals. In MeshLab environment, the 3d models of seals and impressions were manually aligned and then the distance between two sets of 3D points was measured using the filter Hausdorff distance in order to validate a matching. This successful exercise could open the way to the proposal of creating a virtual edition of signacula with 3D models metadata. Furthermore, a research agenda may include the design of a machine learning algorithm for matching of 3D meshes.Item A 3DWeb Application for Weather Forecast Based on WebGL(The Eurographics Association, 2015) Graciano, Alejandro; Rueda, Antonio J.; Feito, Francisco R.; Martínez, Francisco; Mateu Sbert and Jorge Lopez-MorenoManagement, interpretation and visualization of geoscientific and atmospherical information is a major problem for the geoscientist and for a correct diffusion, due to its high volume, complexity, spatiotemporal dimension and three-dimensional nature. As a result, development of software tools for integration, exploration and graphical analysis of the growing amount of available geodata is of great importance. In the last decade a trend towards the implementation of these tools as web applications has consolidated because of its benefits: universal access, permanent availability and ease of collaborative use. However until recently Web development technologies have been ill-equipped for implementing interactive 2D and 3D applications dealing with large amounts of data as required by many geoscience applications. The support of WebGL by most modern browsers has changed this situation and promises to revolutionize the Web in the next few years with a new generation of visually appealing, high performance interactive applications. In this work we describe the technologies for 3D Web and their use in the context of atmospherical data using a 3D weather information application as case study.Item The Social Picture: Advanced Image Analysis Applications(The Eurographics Association, 2017) Milotta, Filippo L. M.; Bellocchi, Michele; Battiato, Sebastiano; Andrea Giachetti and Paolo Pingi and Filippo StancoIn The Social Picture (TSP) an huge amount of crowdsourced social images can be collected and explored. We distinguish three main kind of events: public, private and cultural heritage related ones. The framework embeds a number of advanced Computer Vision algorithms, able to capture the visual content of images and organize them in a semantic way. In this paper we employ VisualSFM (VSFM) to add new features in TSP through the computation of a 3D sparse reconstruction of a collection within TSP. VisualSFM creates a N-View Match (NVM) file as output. Starting from this NVM file, which characterizes the 3D sparse reconstruction, we are able to build two important relationships: the one between cameras and points and the one between cameras themselves. Using these relationships, we implemented two advanced Image Analysis applications. In the first one, we consider the cameras as nodes in a fully connected graph in which the edges weights are equal to the number of matches between cameras. The spanning tree of this graph is used to explore images in a meaningful way, obtaining a scene summarization. In the second application, we define three kinds of density maps with relation to image features: density map, weighted-density map and social-weighted-density map. Results of a test conducted on a collection from TSP is shown.Item Kinamo: Gait Analysis System(The Eurographics Association, 2012) Martínez, H.; Gil-Gómez, J. A.; Martínez-Gramage, J.; Juan, M. C.; Isabel Navazo and Gustavo PatowThe gait analysis is a fundamental technique for functional assessment of patients with gait problems. This analysis is generally available to few patients because the systems needed to carry it out have a high cost. In this paper, we present a novel system, Kinamo, which allows to decrease drastically the cost when performing the gait analysis using Kinect cameras, which not only allows the reduction of cost, but also facilitates the acquisition conditions.Item gVirtualXRay: Virtual X-Ray Imaging Library on GPU(The Eurographics Association, 2017) Sujar, Aaron; Meuleman, Andreas; Villard, Pierre-Frederic; García, Marcos; Vidal, Franck; Tao Ruan Wan and Franck VidalWe present an Open-source library called gVirtualXRay to simulate realistic X-ray images in realtime. It implements the attenuation law (also called Beer-Lambert) on GPU. It takes into account the polychromatism of the beam spectra as well as the finite size of X-ray tubes. The library is written in C++ using modern OpenGL. It is fully portable and works on most common desktop/laptop computers. It has been tested on MS Windows, Linux, and Mac OS X. It supports a wide range of windowing solutions, such as FLTK, GLUT, GLFW3, Qt4, and Qt5. The library also offers realistic visual rendering of anatomical structures, including bones, liver, diaphragm and lungs. The accuracy of the X-ray images produced by gVirtualXRay's implementation has been validated using Geant4, a well established state-of-the-art Monte Carlo simulation toolkit developed by CERN. gVirtualXRay can be used in a wide range of applications where fast and accurate X-ray simulations from polygon meshes are needed, e.g. medical simulators for training purposes, simulation of tomography data acquisition with patient motion to include artefacts in reconstructed CT images, and deformable registration. Our application example package includes real-time respiration and X-ray simulation, CT acquisition and reconstruction, and iso-surfacing of implicit functions using Marching Cubes.
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