VMV13

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https://diglib.eg.org/handle/10.2312/1017

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Browsing VMV13 by Subject "and object representations"

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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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    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).