SGP14: Eurographics Symposium on Geometry Processing - Posters
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Geodesic Voronoi Diagrams with Polyline Generators
[meta data] [files:
Chunxu Xu
;
Yong-Jin Liu
;
Qian Sun
;
Jinyan Li
;
Ying He
Irregular Model Synthesis via Boundary Consistency Analysis
[meta data] [files:
Mofei Song
;
Zhengxing Sun
;
Feiqian Zhang
Depth-layer Architecture Reconstruction From Image Collections
[meta data] [files:
Yong Hu
;
Bei Chu
;
Yue Qi
Statistical Mesh Shape Analysis with Nonlandmark Nonrigid Registration
[meta data] [files:
Jan Dupej
;
Vaclav Krajicek
;
Jana Veleminska
;
Josef Pelikan
Learning Geometric Primitives in Point Clouds
[meta data] [files:
M. Caputo
;
K. Denker
;
M. Franz
;
P. Laube
;
G. Umlauf
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Item Geodesic Voronoi Diagrams with Polyline Generators(The Eurographics Association, 2014) Chunxu Xu; Yong-Jin Liu; Qian Sun; Jinyan Li; Ying He; Thomas Funkhouser and Shi-Min HuGeodesic Voronoi diagrams (GVDs) defined on triangle meshes with polyline generators are studied in this paper. We introduce a new concept, called local Voronoi diagram, or LVD, which is a weighted Euclidean Voronoi diagram on a mesh triangle. We show that when restricting on a mesh triangle, the GVD is a subset of the LVD, which can be computed by using the existing 2D techniques. Moreover, only two types of mesh faces can contain GVD edges. Guided by our theoretical findings, the geodesic Voronoi diagram with polyline generators can be built in O(nN logN) time and takes O(nN) space on an n-face mesh with m generators, where N = maxfm;ng.Item Irregular Model Synthesis via Boundary Consistency Analysis(The Eurographics Association, 2014) Mofei Song; Zhengxing Sun; Feiqian Zhang; Thomas Funkhouser and Shi-Min HuThe detailed 3D environment becomes an essential way for offering the richest user experience in the digital entertainment or virtual reality application. Model synthesis [Mer07,MM08,MM09,MM11] is one of the effective methods to create 3D complex shapes from an example. Compared with other methods, this method can realize multidirectional extending easily. Besides, it is a general-purpose modeling tool, which can accept many different example models. One problem of prior work in model synthesis is that it can only extend example models on the regular grid structure. It is inefficient when people need to create some non-parallel or curved structures, which are more popular in the real world. To solve it, we extend the previous adjacent constraint by relaxing the boundary matching constraint, and the constraint is called generalized adjacent constraint. Through a boundary consistency analysis, more adjacent relation can be found to support synthesis on the irregular structure. Then an optimization framework is introduced to refine the synthesis result by maximizing an energy function.Item Depth-layer Architecture Reconstruction From Image Collections(The Eurographics Association, 2014) Yong Hu; Bei Chu; Yue Qi; Thomas Funkhouser and Shi-Min HuAn image-based modeling method is presented to generate a textured 3D model of architecture with a structure of multiple floors and depth layers. In the domain of image-based architecture modeling, it is still a challenging problem to deal with architecture in multilayered structure. We propose a statistic-based top-bottom segmentation algorithm to divide the 3D point cloud generated by structure-from-motion (SFM) method into different floors. For each floor with depth layers, we present a repetition based depth-layer decomposition algorithm to separate the front and back layers. Finally, architecture components are modeled to construct a textured 3D model. Our system has the distinct advantage of producing realistic architecture models with true depth values between front and back layers, which is demonstrated by multiple examples in the paper.Item Construction of G3 Conic Spline Interpolation(The Eurographics Association, 2014) Long Ma; Caiming Zhang; Thomas Funkhouser and Shi-Min HuIn this paper, a new method to interpolate a sequence of ordered points with conic splines is presented. The degree of continuity at joints of the resulting splines can reach G3 while the number of curvature extrema is reduced to a minimum. The construction process is not based on parametrization, but basic geometric elements. A new geometric concept called Chord-Tangent Ratio which is vital to determine the shape of conic splines is proposed. The main idea of the construction is to merge the constraints of continuity into a function of tangent arguments and Chord-Tangent Ratios, and construct an optimization function to eliminate the curvature extrema, then through an iterative process, for the constraint function to reach its zero point and for the optimization function to reach its minimum. Experiments show that splines constructed by the new method performs well not only in terms of continuity, but also in smoothness.Item Statistical Mesh Shape Analysis with Nonlandmark Nonrigid Registration(The Eurographics Association, 2014) Jan Dupej; Vaclav Krajicek; Jana Veleminska; Josef Pelikan; Thomas Funkhouser and Shi-Min HuThe analysis of shape represented as surface meshes is an important tool in anthropology and biomedicine for the study of aging, post-treatment development or sexual dimorphism. Most approaches rely on nonrigid registration using manually placed homologous landmarks, it is however often the case that some regions cannot be landmarked due to the lack of clear anatomical features. We therefore present a method of analyzing and visualizing the variability of a set of surface models that does not rely on landmarks for feature matching and uses coherent point drift (CPD), a nonrigid registration algorithm, instead. Our approach is based on the topology transfer of one arbitrarily selected base mesh to all other meshes with the use of CPD. The procedure ensures the identical meanings of corresponding vertices across the sample and allows the use of multivariate statistics even with shapes that would be difficult to process with methods that rely on landmarks for feature-matching.Item Learning Geometric Primitives in Point Clouds(The Eurographics Association, 2014) M. Caputo; K. Denker; M. Franz; P. Laube; G. Umlauf; Thomas Funkhouser and Shi-Min HuPrimitive recognition in 3D point clouds is an important aspect in reverse engineering. We propose a method for primitive recognition based on machine learning approaches. The machine learning approaches used for the classification are linear discriminant analysis (LDA) and multi-class support vector machines (SVM). For the classification process local geometric properties (features) of the point cloud are computed based on point relations, normals, and principal curvatures. For the training phase point clouds are generated using a simulation of a laser scanning device based on ray tracing with an error model. The classification rates of novel, curvaturebased geometric features are compared to known geometric features to prove the effectiveness of the approach.