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Item Enhancing Medical Diagnosis and Treatment Planning through Automated Acquisition and Classification of Bone Fracture Patterns(The Eurographics Association, 2024) Pérez-Cano, Francisco Daniel; Parra-Cabrera, Gema; Camacho-García, Rubén; Jiménez, Juan José; Marco, Julio; Patow, GustavoThe extraction of the main features of a fractured bone area enables subsequent virtual reproduction for bone simulations. Exploring the fracture zone for other applications remains largely unexplored in current research. Recreating and analyzing fracture patterns has direct applications in medical training programs for traumatologists, automatic bone fracture reduction algorithms, and diagnostics. Furthermore, pattern classification aids in establishing treatment guidelines that specialists can follow during the surgical process. This paper focuses on the process of obtaining an accurate representation of bone fractures, starting with computed tomography scans, and subsequently classifying these patterns using a convolutional neural network. The proposed methodology aims to streamline the extraction and classification of fractures from clinical cases, contributing to enhanced diagnosis and medical simulation applications.Item Study of the Influence of User Characteristics on the Virtual Reality Presence(The Eurographics Association, 2018) Mayor, Jesús; Sánchez, Alberto; Raya, Laura; García-Fernández, Ignacio and Ureña, CarlosIn recent years, virtual reality has grown a lot in different areas of application, including ludic, social and research, being used by a large and growing number of users with different profiles. Presence is one of the most distinctive and important features of a virtual reality experience. The aim of this article is to study the most suitable areas of application for users and to analyze the influence of different characteristics of the user's profile in the perceived presence. We have tested the interest applications indicated by 159 subjects and we have designed an immersive virtual reality experience, testing the behavior and performance of 48 users. The results obtained show that gender can influence the perceptual sensation of presence in these types of virtual environments.Item Rendering and Interacting With Volume Models in Immersive Environments(The Eurographics Association, 2018) Fons, Joan; Monclús, Eva; Vázquez, Pere-Pau; Navazo, Isabel; García-Fernández, Ignacio and Ureña, CarlosThe recent advances in VR headsets, such as the Oculus Rift or HTC Vive, at affordable prices offering a high resolution display, has empowered the development of immersive VR applications. data. In this paper we propose an immersive VR system that uses some well-known acceleration algorithms to achieve real-time rendering of volumetric datasets in an immersive VR system. Moreover, we have incorporated different basic interaction techniques to facilitate the inspection of the volume dataset. The interaction has been designed to be as natural as possible in order to achieve the most comfortable, user-friendly virtual experience. We have conducted an informal user study to evaluate the user preferences. Our evaluation shows that our application is perceived usable, easy of learn and very effective in terms of the high level of immersion achieved.Item Muscle Simulation with Extended Position Based Dynamics(The Eurographics Association, 2018) Romeo, Marco; Monteagudo, Carlos; Sánchez-Quirós, Daniel; García-Fernández, Ignacio and Ureña, CarlosRecent research on muscle simulation for Visual Effects relies on numerical methods such as the Finite Element Method or Finite Volume Method. These approaches produce realistic results, but require high computational time and are complex to set up. On the other hand Position Based Dynamics offers a fast and controllable solution to simulate surfaces and volumes, but there is no literature on how to implement constraints that could be used to realistically simulate muscles for digital creatures with this method. In this paper we extend the current state-of-the-art in Position Based Dynamics to efficiently compute realistic skeletal-muscle simulation. In particular we embed muscle fibers in the solver by adding an anisotropic component to the distance constraints between mesh points and apply overpressure to realistically model muscle volume changes under contraction. We also present a technique that consistently provides an internal structure for our muscle volumes. We use this structure to preserve the shape and extract relevant information for the activation of the muscle fibers. Finally, we propose a modification of the Extended Position Based Dynamics algorithm and describe other details for proper simulation of character’'s muscle dynamics.Item Generación de fenómenos naturales mediante la simulación realista de sólidos deformables en Bifrost(The Eurographics Association, 2021) Cruz, José; Jurado, Juan Manuel; Jiménez-Pérez, J. Roberto; Ortega, Lidia; Ortega, Lidia M. and Chica, AntonioLa simulación de fluidos y sólidos deformables ha sido ampliamente estudiada en Informática Gráfica. Existen diferentes soluciones que posibilitan una simulación cada vez más realista en entornos del mundo real. Para ello, los objetos se modelan geométricamente utilizando una malla de partículas. Esto permite la deformación de medios continuos asociando un conjunto de atributos a cada partícula que determinan su comportamiento y el de sus vecinas. En este trabajo se propone una herramienta interdisciplinar con la que generar simulaciones de fenómenos naturales como avalanchas o inundaciones. Gracias a este tipo de simulaciones físicamente realistas se consigue una manera efectiva de predecir y evaluar con un alto nivel de detalle el impacto producido por distintos tipos de desastres naturales.Item Simulation Based Initial Feasibility Analysis Pipeline for Small-sized Part Picking(The Eurographics Association, 2022) Mendizabal-Arrieta, Iñigo; Tammaro, Antonio; Ojer, Marco; Lin, Xiao; Posada, Jorge; Serrano, AnaRandom bin picking is still one of the main tasks for robotics in the current days. When the environment is very cluttered, the calculation of grasping positions can be highly demanding in terms of time and computing power. To ease the computation load, some parts arranging operations can be performed before the segmentation stage. For instance, for small and light parts, a feeder-vibrating table system can be used to separate the components, allowing them to be easily grasped, and increasing the overall performance of the solution. However, as the geometry and requirements for piece type are different, one or more feasibility tests need to be done for each case. These analyses are usually very time and cost intensive and require the use of expensive hardware such as robots, grippers, and prototype cells. The use of virtual reproductions of the environment like digital twins or physical-based simulations could help reduce the time and effort spent on designing the settings, nevertheless, their correct configuration is not trivial. This paper presents a simulation based analysis method for picking small-sized parts. It aims to supply the tools and define a streamlined procedure for efficient feasibility testing. Those concepts are applied in a specific bin picking scenario of multiple small electronic components. For each part type, a set of case-specific initial and boundary conditions are taken into account, then a series of performance metrics for both bin and vibrating table part picking are computed. The obtained information is decisive to make strategic decisions regarding the hardware requirements, the profitability, and the success probability of the project.Item ISSIGraph: An Open Source Multi-platform C++ Tool for Rapid 2D/3D Wireframe Sketching(The Eurographics Association, 2021) Jiménez de Parga, Carlos; ; Ortega, Lidia M. and Chica, AntonioRapid sketch modelling and Computer-Aided Design (CAD) initiation are increasingly demanded activities in the creative and educational areas. For this reason, this paper presents a cross-platform C++ toolkit with the aim to facilitate the illustration of technical concepts in a fast way using basic quadric objects, Bézier and NURBS surfaces with a wireframe representation. This tool was designed using Software Engineering principles guided by a basic Rational Unified Process (RUP) methodology with the application of the Unified Modelling Language (UML). This tool perfectly works in all computers with very elemental 3D graphics hardware and with OpenGL support. The resulting benchmarks demonstrate that ISSIGraph has a very small CPU footprint that make it suitable for any platform. As a consequence, this application is well suited for rapid 2D/3D project sketching in the creative and engineering fields, as well as an initiation to CAD techniques for students and computer fans.Item An Efficient Point Selection Process over a Meshlet-structured Point Cloud(The Eurographics Association, 2024) Ortega, Lidia M.; Fernández, Juan Carlos; Collado, José Antonio; Feito, J. Francisco R.; Marco, Julio; Patow, GustavoVisualizing and interacting increasingly large and dense point clouds imposes the need for new methods with real-time results, where most common solutions imply a disadvantage greater than their benefit. Among the recent software and hardware advances in computer graphics and visualization, it is possible to take the concept of meshlet as a clustering of nearby points in space; this nature can bring a considerable improvement in the interaction process over the classical brute-force based algorithm, similar to common three-dimensional spatial structures. This work implements the point selection process over a meshlet-structured point cloud, assessing its performance against alternative methods and validating its correctness by visualizing the selection result on a graphical interface. By exploiting the meshlet instead of building additional spatial structures, the method's execution time can be optimized, as well as the use of the system's main memory.Item Generation Process of Intrinsic Images Dataset Through Physically-based Rendering(The Eurographics Association, 2021) Rodríguez, Ignacio Moral; López, Alfonso; Jiménez-Perez, J. Roberto; Feito, Francisco R.; Ortega, Lidia; Jurado, Juan M.; Ortega, Lidia M. and Chica, AntonioEl problema denominado Intrinsic Image Decomposition sigue siendo un desafío por resolver en informática gráfica. Aunque el uso de arquitecturas de aprendizaje profundo supondría un avance significativo, los conjuntos de datos de entrenamiento utilizados son aún reducidos. En este estudio se presenta una metodología para la generación de imágenes y su descomposición en varios canales haciendo uso del motor de renderizado Mitsuba2. Para ello, se ha modelado un escenario natural en el que coexisten distintos tipos de vegetación sobre un terreno. En torno a este escenario, se define una trayectoria sobre la que orbita la cámara para generar un conjunto de imágenes desde distintos puntos de vista de forma automática. Como resultado, se proporcionan conjuntos de datos obtenidos a partir de entornos naturales sintéticos formados por las siguientes capas para cada imagen: mapa de normales, iluminación, albedo y mapa de profundidad. Este desarrollo supone un punto de partida para el estudio del cálculo de la iluminación en entornos reales complejos mediante enfoques basados en aprendizaje profundo.Item Depth Map Repairing for Building Reconstruction(The Eurographics Association, 2018) Andújar, Carlos; Argudo, Oscar; Besora, Isaac; Brunet, Pere; Chica, Antoni; Comino Trinidad, Marc; García-Fernández, Ignacio and Ureña, CarlosStructure-from-motion along with multi-view stereo techniques jointly allow for the inexpensive scanning of 3D objects (e.g. buildings) using just a collection of images taken from commodity cameras. Despite major advances in these fields, a major limitation of dense reconstruction algorithms is that correct depth/normal values are not recovered on specular surfaces (e.g. windows) and parts lacking image features (e.g. flat, textureless parts of the facade). Since these reflective properties are inherent to the surface being acquired, images from different viewpoints hardly contribute to solve this problem. In this paper we present a simple method for detecting, classifying and filling non-valid data regions in depth maps produced by dense stereo algorithms. Triangles meshes reconstructed from our repaired depth maps exhibit much higher quality than those produced by state-of-the-art reconstruction algorithms like Screened Poisson-based techniques.