G. Dupuy, B. Jobard, S. Guillon, N. Keskes, D. Komatitsch
In order to deal with the heavy trend in size increase of volumetric datasets, research in isosurface extraction has focused in the past few years on related aspects such as surface simplification and load balanced parallel algorithms. We present in this paper a parallel, bloc-wise extension of the tandem algorithm [Attali et al. 2005], which simplifies on the fly an isosurface being extracted. Our approach minimizes the overall memory consumption using an adequate bloc splitting and merging strategy and with the introduction of a component dumping mechanism that drastically reduces the amount of memory needed for particular datasets such as those encountered in geophysics. As soon as detected, surface components are migrated to the disk along with a meta-data index (oriented bounding box, volume, etc) that will allow further improved exploration scenarios (small components removal or particularly oriented components selection for instance). For ease of implementation, we carefully describe a master and slave algorithm architecture that clearly separates the four required basic tasks. We show several results of our parallel algorithm applied on a 7000x1600x2000 geophysics dataset.
为了应对体积数据集规模急剧增长的趋势，近年来等值面提取的研究主要集中在曲面简化和负载均衡并行算法等相关方面。我们在本文中提出了对串联算法的并行、分组扩展[Attali et al. 2005]，它简化了正在提取的等值面。我们的方法使用适当的块分割和合并策略，并引入组件转储机制，从而最大限度地减少了特定数据集(如地球物理学中遇到的数据集)所需的内存量，从而最大限度地减少了总体内存消耗。一旦检测到，表面组件将与元数据索引(定向边界框，体积等)一起迁移到磁盘，这将允许进一步改进勘探场景(例如小组件移除或特定定向组件选择)。为了便于实现，我们仔细描述了一个主从算法架构，它清楚地分离了四个所需的基本任务。我们展示了并行算法在7000x1600x2000地球物理数据集上的几个应用结果。
{"title":"Isosurface extraction and interpretation on very large datasets in geophysics","authors":"G. Dupuy, B. Jobard, S. Guillon, N. Keskes, D. Komatitsch","doi":"10.1145/1364901.1364932","DOIUrl":"https://doi.org/10.1145/1364901.1364932","url":null,"abstract":"In order to deal with the heavy trend in size increase of volumetric datasets, research in isosurface extraction has focused in the past few years on related aspects such as surface simplification and load balanced parallel algorithms.\u0000 We present in this paper a parallel, bloc-wise extension of the tandem algorithm [Attali et al. 2005], which simplifies on the fly an isosurface being extracted. Our approach minimizes the overall memory consumption using an adequate bloc splitting and merging strategy and with the introduction of a component dumping mechanism that drastically reduces the amount of memory needed for particular datasets such as those encountered in geophysics. As soon as detected, surface components are migrated to the disk along with a meta-data index (oriented bounding box, volume, etc) that will allow further improved exploration scenarios (small components removal or particularly oriented components selection for instance). For ease of implementation, we carefully describe a master and slave algorithm architecture that clearly separates the four required basic tasks. We show several results of our parallel algorithm applied on a 7000x1600x2000 geophysics dataset.","PeriodicalId":216067,"journal":{"name":"Symposium on Solid and Physical Modeling","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121227984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present an algorithm to triangulate a multi-resolution hierarchical hexagon mesh. The triangulation provides good triangle strips, which result in efficient rendering of the hexagon mesh, and well proportioned triangles, which avoid rendering artifacts.
{"title":"Triangulation of hierarchical hexagon meshes","authors":"Matthew Guenette, A. J. Stewart","doi":"10.1145/1364901.1364944","DOIUrl":"https://doi.org/10.1145/1364901.1364944","url":null,"abstract":"We present an algorithm to triangulate a multi-resolution hierarchical hexagon mesh. The triangulation provides good triangle strips, which result in efficient rendering of the hexagon mesh, and well proportioned triangles, which avoid rendering artifacts.","PeriodicalId":216067,"journal":{"name":"Symposium on Solid and Physical Modeling","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122392661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An algorithm and implementation is presented to compute the exact arrangement induced by arbitrary algebraic surfaces on a parametrized ring dupin cyclide. The family of dupin cyclides contains as a special case the torus. The intersection of an algebraic surface of degree n with a reference cyclide is represented as a real algebraic curve of bi-degree (2n, 2n) in the two-dimensional parameter space of the cyclide. We use eigenwillig and kerber: "exact and efficient 2D-Arrangements of arbitrary algebraic Curves", SODA 2008, to compute a planar arrangement of such curves and extend their approach to obtain more asymptotic information about curves approaching the boundary of the cyclide's parameter space. With that, we can base our implementation on the general software framework by berberich et. al.: "sweeping and maintaining two-dimensional arrangements on surfaces: A first Step", ESA 2007. Our contribution provides the demanded techniques to model the special geometry of surfaces intersecting a cyclide and the special topology of the reference surface of genus one. The contained implementation is complete and does not assume generic position. Our experiments show that the combinatorial overhead of the framework does not harm the efficiency of the method. Our experiments show that the overall performance is strongly coupled to the efficiency of the implementation for arrangements of algebraic plane curves.
{"title":"Exact arrangements on tori and Dupin cyclides","authors":"Eric Berberich, Michael Kerber","doi":"10.1145/1364901.1364912","DOIUrl":"https://doi.org/10.1145/1364901.1364912","url":null,"abstract":"An algorithm and implementation is presented to compute the exact arrangement induced by arbitrary algebraic surfaces on a parametrized ring dupin cyclide. The family of dupin cyclides contains as a special case the torus. The intersection of an algebraic surface of degree n with a reference cyclide is represented as a real algebraic curve of bi-degree (2n, 2n) in the two-dimensional parameter space of the cyclide. We use eigenwillig and kerber: \"exact and efficient 2D-Arrangements of arbitrary algebraic Curves\", SODA 2008, to compute a planar arrangement of such curves and extend their approach to obtain more asymptotic information about curves approaching the boundary of the cyclide's parameter space. With that, we can base our implementation on the general software framework by berberich et. al.: \"sweeping and maintaining two-dimensional arrangements on surfaces: A first Step\", ESA 2007. Our contribution provides the demanded techniques to model the special geometry of surfaces intersecting a cyclide and the special topology of the reference surface of genus one. The contained implementation is complete and does not assume generic position. Our experiments show that the combinatorial overhead of the framework does not harm the efficiency of the method. Our experiments show that the overall performance is strongly coupled to the efficiency of the implementation for arrangements of algebraic plane curves.","PeriodicalId":216067,"journal":{"name":"Symposium on Solid and Physical Modeling","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130806348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Height maps are a very efficient surface representation, initially developed for terrain modeling and visualization. They are also present in other applications, such as mesostructure rendering. However, height maps are incapable of representing overhangs or self-folding surfaces, as well as several occluding objects. In this paper we propose a novel representation to overcome these limitations. A Solid Height-map Set is used to represent arbitrary solid geometry. We also describe a procedure to convert polygonal meshes into our scheme. In addition, we develop a visualization algorithm capable of efficiently rendering this novel representation and implement it using GPU programming. Results achieve an order of magnitude in memory savings as well as high performance independent of the original mesh size.
{"title":"Solid height-map sets: modeling and visualization","authors":"P. I. N. Santos, Rodrigo de Toledo, M. Gattass","doi":"10.1145/1364901.1364953","DOIUrl":"https://doi.org/10.1145/1364901.1364953","url":null,"abstract":"Height maps are a very efficient surface representation, initially developed for terrain modeling and visualization. They are also present in other applications, such as mesostructure rendering. However, height maps are incapable of representing overhangs or self-folding surfaces, as well as several occluding objects. In this paper we propose a novel representation to overcome these limitations. A Solid Height-map Set is used to represent arbitrary solid geometry. We also describe a procedure to convert polygonal meshes into our scheme. In addition, we develop a visualization algorithm capable of efficiently rendering this novel representation and implement it using GPU programming. Results achieve an order of magnitude in memory savings as well as high performance independent of the original mesh size.","PeriodicalId":216067,"journal":{"name":"Symposium on Solid and Physical Modeling","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116699610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we present a new visibility-based feature extraction algorithm from discrete models as dense point clouds resulting from laser scans. Based on the observation that one can characterize local properties of the surface by what can be seen by an imaginary creature on the surface, we propose algorithms that extract features using an intermediate representation of the model as a discrete volume for computational efficiency. We describe an efficient algorithm for computing the visibility map among voxels, based on the properties of a discrete erosion. The visibility information obtained in this first step is then used to extract the model components (faces, edges and vertices) --- which may be curved---and to compute the topological connectivity graph in a very efficient and robust way. The results are discussed through several examples.
{"title":"Visibility-based feature extraction from discrete models","authors":"A. Chica","doi":"10.1145/1364901.1364951","DOIUrl":"https://doi.org/10.1145/1364901.1364951","url":null,"abstract":"In this paper, we present a new visibility-based feature extraction algorithm from discrete models as dense point clouds resulting from laser scans. Based on the observation that one can characterize local properties of the surface by what can be seen by an imaginary creature on the surface, we propose algorithms that extract features using an intermediate representation of the model as a discrete volume for computational efficiency. We describe an efficient algorithm for computing the visibility map among voxels, based on the properties of a discrete erosion. The visibility information obtained in this first step is then used to extract the model components (faces, edges and vertices) --- which may be curved---and to compute the topological connectivity graph in a very efficient and robust way. The results are discussed through several examples.","PeriodicalId":216067,"journal":{"name":"Symposium on Solid and Physical Modeling","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123084694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yu-Kun Lai, Shimin Hu, Ralph Robert Martin, Paul L. Rosin
3D mesh models are now widely available for use in various applications. The demand for automatic model analysis and understanding is ever increasing. Mesh segmentation is an important step towards model understanding, and acts as a useful tool for different mesh processing applications, e.g. reverse engineering and modeling by example. We extend a random walk method used previously for image segmentation to give algorithms for both interactive and automatic mesh segmentation. This method is extremely efficient, and scales almost linearly with increasing number of faces. For models of moderate size, interactive performance is achieved with commodity PCs. It is easy-to-implement, robust to noise in the mesh, and yields results suitable for downstream applications for both graphical and engineering models.
{"title":"Fast mesh segmentation using random walks","authors":"Yu-Kun Lai, Shimin Hu, Ralph Robert Martin, Paul L. Rosin","doi":"10.1145/1364901.1364927","DOIUrl":"https://doi.org/10.1145/1364901.1364927","url":null,"abstract":"3D mesh models are now widely available for use in various applications. The demand for automatic model analysis and understanding is ever increasing. Mesh segmentation is an important step towards model understanding, and acts as a useful tool for different mesh processing applications, e.g. reverse engineering and modeling by example. We extend a random walk method used previously for image segmentation to give algorithms for both interactive and automatic mesh segmentation. This method is extremely efficient, and scales almost linearly with increasing number of faces. For models of moderate size, interactive performance is achieved with commodity PCs. It is easy-to-implement, robust to noise in the mesh, and yields results suitable for downstream applications for both graphical and engineering models.","PeriodicalId":216067,"journal":{"name":"Symposium on Solid and Physical Modeling","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131879055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To make geometric computation robust against numerical errors is one of the most important issues for practical applications of geometric algorithms. We first review existing approaches to robust geometric computation, and next show that there still remain many difficulties. Finally we discuss possible directions to overcome these difficulties and thus to achieve superrobustness.
{"title":"Toward superrobust geometric computation","authors":"K. Sugihara","doi":"10.1145/1364901.1364905","DOIUrl":"https://doi.org/10.1145/1364901.1364905","url":null,"abstract":"To make geometric computation robust against numerical errors is one of the most important issues for practical applications of geometric algorithms. We first review existing approaches to robust geometric computation, and next show that there still remain many difficulties. Finally we discuss possible directions to overcome these difficulties and thus to achieve superrobustness.","PeriodicalId":216067,"journal":{"name":"Symposium on Solid and Physical Modeling","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130520415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A piecewise quintic interpolation scheme with approximate G1 continuity is presented. For a given triangular mesh of arbitrary topology, one quintic triangular Bézier patch is constructed for each data triangle. Although the resulting surface has G1 continuity at the data vertices, we only require approximate G1 continuity along the patch boundaries so as to lower the patch degree. To reduce the normal discontinuity along boundaries, neighbouring patches are adjusted to have identical normals at the middle point of their common boundary. In most cases, the surfaces generated by this scheme have the same level of visual smoothness compared to an existing sextic G1 continuous interpolation scheme. Further, using the new boundary construction method presented in this paper, better shape quality is observed for sparse data sets than the surfaces of the original G1 continuous scheme, upon which the new scheme is based.
{"title":"Parametric triangular Bézier surface interpolation with approximate continuity","authors":"Yingbin Liu, Stephen Mann","doi":"10.1145/1364901.1364956","DOIUrl":"https://doi.org/10.1145/1364901.1364956","url":null,"abstract":"A piecewise quintic interpolation scheme with approximate G1 continuity is presented. For a given triangular mesh of arbitrary topology, one quintic triangular Bézier patch is constructed for each data triangle. Although the resulting surface has G1 continuity at the data vertices, we only require approximate G1 continuity along the patch boundaries so as to lower the patch degree. To reduce the normal discontinuity along boundaries, neighbouring patches are adjusted to have identical normals at the middle point of their common boundary. In most cases, the surfaces generated by this scheme have the same level of visual smoothness compared to an existing sextic G1 continuous interpolation scheme. Further, using the new boundary construction method presented in this paper, better shape quality is observed for sparse data sets than the surfaces of the original G1 continuous scheme, upon which the new scheme is based.","PeriodicalId":216067,"journal":{"name":"Symposium on Solid and Physical Modeling","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130836245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
View identification is the basal process for solid reconstruction from engineering drawings. A new method is presented to label various views from a section-involved drawing and identify geometric planes through the object at which the sections are to be located. In the approach, a graph representation is developed for describing multiple relationships among various views in the 2D drawing space, and a reasoning technique based on evidence theory is implemented to validate view relations that are used to fold views and sections in the 3D object space. This is the first automated approach which can handle multiple sections in diverse arrangements, especially accommodating the aligned section for the first time. Experimental results are given to show that the proposed solution makes a breakthrough in the field and builds a promising basis for further expansibility, although it is not a complete one.
{"title":"Identification of sections from engineering drawings based on evidence theory","authors":"Jie-Hui Gong, Hui Zhang, Bin Jiang, Jiaguang Sun","doi":"10.1145/1364901.1364907","DOIUrl":"https://doi.org/10.1145/1364901.1364907","url":null,"abstract":"View identification is the basal process for solid reconstruction from engineering drawings. A new method is presented to label various views from a section-involved drawing and identify geometric planes through the object at which the sections are to be located. In the approach, a graph representation is developed for describing multiple relationships among various views in the 2D drawing space, and a reasoning technique based on evidence theory is implemented to validate view relations that are used to fold views and sections in the 3D object space. This is the first automated approach which can handle multiple sections in diverse arrangements, especially accommodating the aligned section for the first time. Experimental results are given to show that the proposed solution makes a breakthrough in the field and builds a promising basis for further expansibility, although it is not a complete one.","PeriodicalId":216067,"journal":{"name":"Symposium on Solid and Physical Modeling","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114817948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper we present a new algorithm which turns an unstructured triangle mesh into a quad-dominant mesh with edges aligned to the principal directions of the underlying geometry. Instead of computing a globally smooth parameterization or integrating curvature lines along a tangent vector field, we simply apply an iterative relaxation scheme which incrementally aligns the mesh edges to the principal directions. The quad-dominant mesh is eventually obtained by dropping the not-aligned diagonals from the triangle mesh. A post-processing stage is introduced to further improve the results. The major advantage of our algorithm is its conceptual simplicity since it is merely based on elementary mesh operations such as edge collapse, flip, and split. The resulting meshes exhibit a very good alignment to surface features and rather uniform distribution of mesh vertices. This makes them very well-suited, e.g., as Catmull-Clark Subdivision control meshes.
{"title":"An incremental approach to feature aligned quad dominant remeshing","authors":"Yu-Kun Lai, L. Kobbelt, Shimin Hu","doi":"10.1145/1364901.1364921","DOIUrl":"https://doi.org/10.1145/1364901.1364921","url":null,"abstract":"In this paper we present a new algorithm which turns an unstructured triangle mesh into a quad-dominant mesh with edges aligned to the principal directions of the underlying geometry. Instead of computing a globally smooth parameterization or integrating curvature lines along a tangent vector field, we simply apply an iterative relaxation scheme which incrementally aligns the mesh edges to the principal directions. The quad-dominant mesh is eventually obtained by dropping the not-aligned diagonals from the triangle mesh. A post-processing stage is introduced to further improve the results. The major advantage of our algorithm is its conceptual simplicity since it is merely based on elementary mesh operations such as edge collapse, flip, and split. The resulting meshes exhibit a very good alignment to surface features and rather uniform distribution of mesh vertices. This makes them very well-suited, e.g., as Catmull-Clark Subdivision control meshes.","PeriodicalId":216067,"journal":{"name":"Symposium on Solid and Physical Modeling","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132246835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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