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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 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 A Moving Least Squares Method for Implant Model Deformation in Computer Aided Orthopedic Surgery for Fractures of Lower Extremities(The Eurographics Association, 2021) RamÃrez, Esmitt; Coto, Ernesto; Silva, F. and Gutierrez, D. and RodrÃguez, 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.; MartÃnez, 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 gVirtualXRay: Virtual X-Ray Imaging Library on GPU(The Eurographics Association, 2017) Sujar, Aaron; Meuleman, Andreas; Villard, Pierre-Frederic; GarcÃa, 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.Item Using Semi-automatic 3D Scene Reconstruction to Create a Digital Medieval Charnel Chapel(The Eurographics Association, 2016) Shui, Wuyang; Maddock, Steve; Heywood, Peter; Craig-Atkins, Elizabeth; Crangle, Jennifer; Hadley, Dawn; Scott, Rab; Cagatay Turkay and Tao Ruan WanThe use of a terrestrial laser scanner (TLS) has become a popular technique for the acquisition of 3D scenes in the fields of cultural heritage and archaeology. In this study, a semi-automatic reconstruction technique is presented to convert the point clouds that are produced, which often contain noise or are missing data, into a set of triangle meshes. The technique is applied to the reconstruction of a medieval charnel chapel. To reduce the computational complexity of reconstruction, the point cloud is first segmented into several components guided by the geometric structure of the scene. Landmarks are interactively marked on the point cloud and multiple cutting planes are created using the least squares method. Then, sampled point clouds for each component are meshed by ball-pivoting. In order to fill the large missing regions on the walls and ground plane, inserted triangle meshes are calculated on the basis of the convex hull of the projection points on the bounding plane. The iterative closest point (ICP) approach and local non-rigid registration methods are used to make the inserted triangle meshes and original model tightly match. Using these methods, we have reconstructed a digital model of the medieval charnel chapel, which not only serves to preserve a digital record of it, but also enables members of t he public to experience the space virtually.Item 3D GIS Based on WebGL for the Management of Underground Utilities(The Eurographics Association, 2017) Jurado, Juan Manuel; Ortega, Lidia; Feito, Francisco R.; Fco. Javier Melero and Nuria PelechanoThis work summarizes a web application related to a research project about underground infrastructures. The aim is to visualize, analyse and manage all underground layers inside 3D urban environments. This is possible using WebGL to develop a web application which may be used from mobile devices. The study of terrain relief to calculate the depth of these infrestructures, the conversion of 2D data to 3D models, the definition of a spatial database and the use of virtual reality to visualize the resulting 3D scene make of this application a useful tool for utility companies dealing with underground infrastructures.Item Industrial Facility Modeling Using Procedural Methods(The Eurographics Association, 2015) Bishop, M. Scott; Max, Nelson; Mateu Sbert and Jorge Lopez-MorenoWe present an end-to-end system for procedurally modeling an industrial facility. The system is a collection of utilities that work together to assemble, lay out, and model a typical industrial facility (e.g. a wastewater treatment plant). A plug-in to the CityEngine (R) procedural modeling application was built in Java (TM) using an open-source framework. The plug-in provides the interface to access the facility assembly and layout engines, the facility rule file and Python script generators, and the OBJ footprint exporter. The system provides functionality for placing the facility model into an existing 3D scene using an established facility location algorithm that maximizes the minimum distance from existing structures in the scene.