CEIG2022

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https://diglib.eg.org/handle/10.2312/2633203

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Browsing CEIG2022 by Subject "Computing methodologies"

Now showing 1 - 7 of 7
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    Cylindrical Transform Slicing of Revolute Parts with Overhangs for Laser Metal Deposition
    (The Eurographics Association, 2022) Montoya-Zapata, Diego; Moreno, Aitor; Ortiz, Igor; Ruiz-Salguero, Oscar; Posada, Jorge; Posada, Jorge; Serrano, Ana
    In the context of Laser Metal Deposition (LMD), temporary support structures are needed to manufacture overhanging features. In order to limit the need for supports, multi-axis machines intervene in the deposition by sequentially repositioning the part. Under multi-axis rotations and translations, slicing and toolpath generation represent significant challenges. Slicing has been partially addressed by authors in multi-axis LMD. However, tool-path generation in multi-axis LMD is rarely touched. One of the reasons is that the required slices for LMD may be strongly non-developable. This fact produces a significant mismatch between the tool-path speeds and other parameters in Parametric space vs. actual Euclidean space. For the particular case of developable slices present in workpieces with cylindrical kernel and overhanging neighborhoods, this manuscript presents a methodology for LMD tool path generation. Our algorithm takes advantage of existing cylindrical iso-radial slicing by generating a path in the (?, z) parameter space and isometrically translating it into the R3 Euclidean space. The presented approach is advantageous because it allows the path-planning of complex structures by using the methods for conventional 2.5-axis AM. Our computer experiments show that the presented approach can be effectively used in manufacturing industrial/mechanical pieces (e.g., spur gears). Future work includes the generation of the machine g-code for actual LMD equipment.
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    Development of a Node-Based Material Editor
    (The Eurographics Association, 2022) Leiro, Luciano Suaya; Garrigó, Marc; Posada, Jorge; Serrano, Ana
    Materials systems are an important element within the development of a renderer for an application such as a video game. Nowadays, the method to build a graphic style for a product involving a real-time engine implies a rendering system supporting a solid and concise materials system, as those well-established in real-time engines such as Unreal or Unity. This study presents an open-source application to serve as an editor of materials consisting of a modern real-time renderer. The application consists of a basic OpenGL real-time rendering engine to visualise 3D geometry and its appearance through the support of a node-based material editor to assemble materials in an intuitive and simple manner, without the use of programming and little technical knowledge. The culmination of the project and the achievement of its objectives was satisfactory. We concluded that this work can be used as a reference to understand real-time material systems and renderers and its state of the art in the video games industry.
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    DriveRNN: Predicting Drivers' Attention with Deep Recurrent Networks
    (The Eurographics Association, 2022) Lasheras-Hernandez, Blanca; Masia, Belen; Martin, Daniel; Posada, Jorge; Serrano, Ana
    Lately, the automotive industry has experienced a significant development led by the ambitious objective of creating an autonomous vehicle. This entails understanding driving behaviors in different environments, which usually requires gathering and analyzing large amounts of behavioral data from many drivers. However, this is usually a complex and time-consuming task, and data-driven techniques have proven to be a faster, yet robust alternative to modeling drivers' behavior. In this work, we propose a deep learning approach to address this challenging problem. We resort to a novel convolutional recurrent architecture to learn spatio-temporal features of driving behaviors based on RGB sequences of the environment in front of the vehicle. Our model is able to predict drivers' attention in different scenarios while outperforming competing works by a large margin.
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    Guided Modeling of Natural Scenarios: Vegetation and Terrain
    (The Eurographics Association, 2022) Collado, José Antonio; López, Alfonso; Pérez, Juan Roberto Jiménez; Ortega, Lidia M.; Jurado, Juan M.; Feito, Francisco; Posada, Jorge; Serrano, Ana
    The generation of realistic natural scenarios is a longstanding and ongoing challenge in Computer Graphics. LiDAR (Laser Imaging Detection and Ranging) point clouds have been gaining interest for the representation and analysis of real-world scenarios. However, the output of these sensors is conditioned by several parameters, including, but not limited to, distance to scanning target, aperture angle, number of laser beams, as well as systematic and random errors for the acquisition process. Hence, LiDAR point clouds may present inaccuracies and low density, thus hardening their visualization. In this work, we propose reconstructing the surveyed environments to enhance the point cloud density and provide a 3D representation of the scenario. To this end, ground and vegetation layers are detected and parameterized to allow their reconstruction. As a result, point clouds of any required density can be modeled, as well as 3D realistic natural scenarios that may lead to procedural generation through their parameterization.
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    Interactive Visualization of Historical Fabrics at Yarn Level using Sphere Tracing
    (The Eurographics Association, 2022) Pérez-Aixendri, Manolo; Gimeno, Jesús; Portalés, Cristina; Casanova-Salas, Pablo; Posada, Jorge; Serrano, Ana
    In this paper we present preliminary results of a new approach for interactive visualization of historical fabrics at yarn level based on models using Signed Distance Functions. They are compared with the results of Virtual Loom, an interactive application for rendering historical fabrics from the 15th to the 19th century, resulting from the European SilkNow project [PSA*18]. Yarns used on these fabrics has an special complexity due to a metallic cover that appears in some elements of the fabric. This new approach is based on rendering using Sphere Tracing. We will propose a signed distance function that allows both the visualization of a single yarn and a complete fabric in real time.
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    A Modular Authoring Tool for Atmospheric Cloud Modelling
    (The Eurographics Association, 2022) Rodríguez-Hernández, Darío; García-Fernández, Ignacio; Posada, Jorge; Serrano, Ana
    Modelling of atmospheric effects and, in particular, of clouds is a recurrent topic in computer graphics. Achieving realistic results poses a great challenge, and manual modelling of such complex structures is unfeasible in production. The use of procedural techniques, either through simulation or heuristic methods, is, thus, frequent. In this work we propose a model that allows atmospheric cloud modelling with small computational effort and a good degree of control by the modeller, speeding up the artistic process. The model is designed hierarchically, can be extended easily due to its modular structure and it allows an intuitive control through a graphical user interface. The tests show a variety of effects that can be generated, and the influence of the different parameters on the render time of the final scene.
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    Synthesis of Reeb Graph and Morse Operators from Level Sets of a Boundary Representation
    (The Eurographics Association, 2022) Pareja-Corcho, Juan; Montoya-Zapata, Diego; Cadavid, Carlos; Moreno, Aitor; Posada, Jorge; Arenas-Tobon, Ketzare; Ruiz-Salguero, Oscar; Posada, Jorge; Serrano, Ana
    In the context of Industrie 4.0, it is necessary for several applications, to encode characteristics of a Boundary Representation of a manifold M in an economical manner. Two related characterizations of closed B-Reps (and the solid they represent) are (1) medial axis and (2) Reeb Graph. The medial axis of a solid region is a non-manifold mixture of 1-simplices and 2- simplices and it is expensive to extract. Because of this reason, this manuscript concentrates in the work-flow necessary to extract the Reeb Graph of the B-Rep. The extraction relies on (a) tests of geometric similarities among slices of M and (b) characterization of the topological transitions in the slice sequence of M. The process roughly includes: (1) tilt of the B-Rep to obtain an unambiguous representation of the level sets ofM,(2) identification and classification of the topological transitions that arise between consecutive level sets, (3) sample of Reeb graph vertices inside the material regions defined by the level sets, (4) creation of Reeb graph edges based on the type of topological transition and the 2D similarity among material regions of consecutive levels. Although the Reeb Graph is a topological construct, geometrical processing is central in its synthesis and compliance with the Nyquist-Shannon sampling interval is crucial for its construction. Future work is needed on the extension of our methodology to account for manifolds with internal voids or nested solids.