VMV: Vision, Modeling, and Visualization

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https://diglib.eg.org/handle/10.2312/1013

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Browsing VMV: Vision, Modeling, and Visualization by Subject "and object representations"

Now showing 1 - 6 of 6
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    Comparative Evaluation of Feature Line Techniques for Shape Depiction
    (The Eurographics Association, 2014) Lawonn, Kai; Baer, Alexandra; Saalfeld, Patrick; Preim, Bernhard; Jan Bender and Arjan Kuijper and Tatiana von Landesberger and Holger Theisel and Philipp Urban
    This paper presents a qualitative evaluation of feature line techniques on various surfaces. We introduce the most commonly used feature lines and compare them. The techniques were analyzed with respect to the degree of realism in comparison with a shaded image with respect to the aesthetic impression they create. First, a pilot study with 20 participants was conducted to make an inquiry about their behavior and the duration. Based on the result of the pilot study, the final evaluation was carried out with 129 participants. We evaluate and interpret the trial results by using the Schulze method and give recommendations for which kind of surface, which feature line technique is most appropriate.
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    Instant Level-of-Detail
    (The Eurographics Association, 2011) Grund, Nico; Derzapf, Evgenij; Guthe, Michael; Peter Eisert and Joachim Hornegger and Konrad Polthier
    Highly detailed models are commonly used in computer games and other interactive rendering applications. In this context, static levels-of-detail are frequently used to achieve real-time frame rates. While this is a simple solution to improve the rendering performance, the additional geometry needs to be stored and loaded into graphics memory. This is especially problematic in online applications, where the data needs to be transmitted over a possibly slow connection. On the other hand, consumer level computers are usually equipped with a graphics card that can be used for general purpose parallel computing. Based on this observation, we propose a high-quality parallel mesh simplification algorithm based on the quadric error metric. The simplification performance can compete with the time required to load additional meshes from a local hard disk.
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    Level of Detail for Real-Time Volumetric Terrain Rendering
    (The Eurographics Association, 2013) Scholz, Manuel; Bender, Jan; Dachsbacher, Carsten; Michael Bronstein and Jean Favre and Kai Hormann
    Terrain rendering is an important component of many GIS applications and simulators. Most methods rely on heightmap-based terrain which is simple to acquire and handle, but has limited capabilities for modeling features like caves, steep cliffs, or overhangs. In contrast, volumetric terrain models, e.g. based on isosurfaces can represent arbitrary topology. In this paper, we present a fast, practical and GPU-friendly level of detail algorithm for large scale volumetric terrain that is specifically designed for real-time rendering applications. Our algorithm is based on a longest edge bisection (LEB) scheme. The resulting tetrahedral cells are subdivided into four hexahedra, which form the domain for a subsequent isosurface extraction step. The algorithm can be used with arbitrary volumetric models such as signed distance fields, which can be generated from triangle meshes or discrete volume data sets. In contrast to previous methods our algorithm does not require any stitching between detail levels. It generates crack free surfaces with a good triangle quality. Furthermore, we efficiently extract the geometry at runtime and require no preprocessing, which allows us to render infinite procedural content with low memory consumption.
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    Resolving Twisted Surfaces within an Iterative Refinement Surface Reconstruction Approach
    (The Eurographics Association, 2012) Annuth, Hendrik; Bohn, Christian-A.; Michael Goesele and Thorsten Grosch and Holger Theisel and Klaus Toennies and Bernhard Preim
    We present a method which resolves twisted surface regions within a surface reconstruction approach that uses local refinement operations to iteratively fit a surface into an unorganized point cloud. We show that this local operation can be integrated reliably and efficiently, although resolving twisted surfaces is not a local operation since it may cause modifications up to one half of the entire surface. We introduce a novel data structure called the minimal edge front that enables efficiently retrieving topological information from the surface under investigation. Equipped with this operation the algorithm is able to robustly handle huge point-clouds of complex closed and also not closed objects like landscapes.
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    Structure-aware Stylization of Mountainous Terrains
    (The Eurographics Association, 2017) Kratt, Julian; Eisenkeil, Ferdinand; Spicker, Marc; Wang, Yunhai; Weiskopf, Daniel; Deussen, Oliver; Matthias Hullin and Reinhard Klein and Thomas Schultz and Angela Yao
    We present a method for the stylization of mountainous terrains that allows creating abstract representations in different rendering styles. Our method consists of two major components: structure-aware terrain filtering and streamline-based hatching. For a given input terrain we compute different Levels-of-Detail (LoD) according to a crest line oriented importance measure and then filter each LoD accordingly. We generate flow fields for each LoD and compute streamlines to direct the production of hatching lines. The combination of crest and silhouette lines with streamline-based hatching allows us to create a variety of styles in different Levels-of-Detail. We evaluate our method using several terrains and demonstrate the effectiveness of our method by composing a number of different illustration styles.
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    A Tracking Approach for the Skeletonization of Tubular Parts of 3D Shapes
    (The Eurographics Association, 2013) Garro, Valeria; Giachetti, Andrea; Michael Bronstein and Jean Favre and Kai Hormann
    In this paper we propose a new simple and efficient method to characterize shapes by segmenting their elongated parts and characterizing them with their centerlines. We call it Tubular Section Tracking, because it consists of slicing the interested volume along different directions, tracking centroids of the extracted sections with approximately constant centroid position, area and eccentricity and refining the extracted lines with a post processing step removing bad branches and centering, joining and extending the relevant ones. We show that, even using just a few slicing directions (in some cases even just three perpendicular directions), the method is able to obtain good results, approximately pose independent and that the extracted lines can be more informative on the relevant feature of the objects than the classical skeletal lines extracted as subsets of the medial axis. Estimated lines can be used to segment shapes into meaningful parts and compute useful parameters (e.g. length, diameters).