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A Survey of CAD Model Simplification Techniques for Physics-based Simulation Applications
"... This document contains the draft version of the following paper: A. Thakur, A.G. Banerjee, and S.K. Gupta. A survey of CAD model simplification techniques for physics-based simulation applications. Computer Aided Design, ..."
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Cited by 21 (1 self)
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This document contains the draft version of the following paper: A. Thakur, A.G. Banerjee, and S.K. Gupta. A survey of CAD model simplification techniques for physics-based simulation applications. Computer Aided Design,
Three-Dimensional Constrained Delaunay Triangulation: A Minimalist Approach
, 1999
"... In this paper we summarize our experiences with 3D constrained Delaunay triangulation algorithms for industrial applications. In addition, we report a robust implementation process for constructing 3D constrained triangulations from initial unconstrained triangulations, based on a minimalist appro ..."
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Cited by 20 (8 self)
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In this paper we summarize our experiences with 3D constrained Delaunay triangulation algorithms for industrial applications. In addition, we report a robust implementation process for constructing 3D constrained triangulations from initial unconstrained triangulations, based on a minimalist approach, in which we minimize the use of geometrical operations such as intersections. This is achieved by inserting Steiner points on missing constraining edges and faces in the initial unconstrained triangulations. This approach allowed the generation of tetrahedral meshes for arbitrarily complex 3D domains.
CHF: A scalable topological data structure for tetrahedral meshes
- In: Proceedings SIBGRAPI
, 2005
"... Abstract. This work introduces a scalable topological data structure for manifold tetrahedral meshes called Compact Half–Face (CHF). It provides a high degree of scalability, since it is able to optimize the memory consumption / execution time ratio for different applications and data by using featu ..."
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Cited by 13 (1 self)
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Abstract. This work introduces a scalable topological data structure for manifold tetrahedral meshes called Compact Half–Face (CHF). It provides a high degree of scalability, since it is able to optimize the memory consumption / execution time ratio for different applications and data by using features of its different levels. An object–oriented API using class inheritance and virtual instantiation enables a unique interface for each function at any level. CHF requires very few memory, is simple to implement and easy to use, since it substitutes pointers by container of integers and basic bitwise rules.
Intersecting and Trimming Parametric Meshes on Finite-Element Shells
- INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
, 2000
"... We present an algorithm for intersecting finite-element meshes defined on parametric surface patches. The intersection curves are modeled precisely and both meshes are adjusted to the newly formed borders, without unwanted reparametrizations. The algorithm is part of an interactive shell modeling pr ..."
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Cited by 9 (2 self)
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We present an algorithm for intersecting finite-element meshes defined on parametric surface patches. The intersection curves are modeled precisely and both meshes are adjusted to the newly formed borders, without unwanted reparametrizations. The algorithm is part of an interactive shell modeling program that has been used in the design of large offshore oil structures. To achieve good interactive response, we represent meshes with a topological data structure that stores its entities in spatial indexing trees instead of linear lists. These trees speed up the intersection computations required to determine points of the trimming curves; moreover, when combined with the topological information, they allow remeshing using only local queries.
Representations for Cognitive Vision: A Review of Appearance-Based, Spatio-Temporal, and Graph-Based Approaches
- ELECTRONIC LETTERS ON COMPUTER VISION AND IMAGE ANALYSIS 7(2):35-61, 2008
, 2008
"... The emerging discipline of cognitive vision requires a proper representation of visual information including spatial and temporal relationships, scenes, events, semantics and context. This review article summarizes existing representational schemes in computer vision which might be useful for cognit ..."
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Cited by 5 (1 self)
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The emerging discipline of cognitive vision requires a proper representation of visual information including spatial and temporal relationships, scenes, events, semantics and context. This review article summarizes existing representational schemes in computer vision which might be useful for cognitive vision, and discusses promising future research directions. The various approaches are categorized according to appearance-based, spatio-temporal, and graph-based representations for cognitive vision. While the representation of objects has been covered extensively in computer vision research, both from a reconstruction as well as from a recognition point of view, cognitive vision will also require new ideas how to represent scenes. We introduce new concepts for scene representations and discuss how these might be efficiently implemented in future cognitive vision systems.
A Topologically-based Framework for Simulating Complex Geological Processes
- In press, AAPG Hedberg Conference Special Volume
, 1998
"... Earth scientists acquire and interpret a variety of data in an attempt to define the best description of subsurface geological structures, or an earth model, as the data permit. The generation of numerical meshes derived from an earth model is a necessary critical step to provide specific data repre ..."
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Cited by 5 (3 self)
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Earth scientists acquire and interpret a variety of data in an attempt to define the best description of subsurface geological structures, or an earth model, as the data permit. The generation of numerical meshes derived from an earth model is a necessary critical step to provide specific data representations such as finite difference grids or finite element meshes, including the model geometry and associated physical properties for simulation applications. The construction of geological, or earth, models has been a challenge not only due to the scarcity of subsurface data but also because of the geometrical complexity of geological structures. Since typical geological structures (e.g., fractures, faults, salt domes) evolve with time due to various physical processes such as compaction, we use a topological framework to create and maintain earth models that allow the geometry to be modified during simulations and with new interpretations. In this paper we describe a framework used to create a reference model defining a spatial partition, which is used to represent multi-material objects. Multi-resolution and multi-structure meshes can be associated as attributes to each cell of the reference model, making it possible to have a flexible mesh management environment for numerical simulations. Typical applications in geosciences are reservoir simulation, basin-wide heat and fluid transfer, and propagation of seismic waves. Because these applications may require significant computational resources, we use this framework to provide critical adjacency information for the spatial domain decomposition used in parallel computing. Application of these techniques is not restricted to geosciences. They can also be applied to engineering fields that involve large deformations, such a...
Effective Programming of Combinatorial Maps using COMA- A C++ Framework for Combinatorial Maps
, 2006
"... Combinatorial maps and pyramids have been studied in great detail in the past, and it has been shown that this concept is advantageous for many applications in the field of image processing and pattern recognition by providing means to store information of the topological relations of the represente ..."
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Cited by 3 (1 self)
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Combinatorial maps and pyramids have been studied in great detail in the past, and it has been shown that this concept is advantageous for many applications in the field of image processing and pattern recognition by providing means to store information of the topological relations of the represented data. In the course of these studies, the properties of combinatorial maps have been investigated using different sets of permutations, different operations and different algorithms. In each case new software had to be created in order to conduct experiments, as the existing programs were designed to work only for a specific model. Due to the complexity of combinatorial maps, the implementation of such a software is a time and resource intensive task. Thus these programming efforts were often responsible for delaying the presentation of new results in the past. This paper presents COMA- a C++ framework for combinatorial maps- that has been created during recent studies of combinatorial maps, motivated by this problem. Using an object oriented approach, COMA was specifically designed to allow an efficient and quick integration of changes to the model of combinatorial maps used, as well as the implementation of new algorithms. As a consequence COMA significantly reduces the amount of time needed to set up new experiments. 1
CHE: A scalable topological data structure for triangular meshes
, 2005
"... Abstract. This work introduces a scalable topological data structure for manifold triangular meshes called Compact Half–Edge (CHE). It provides a high degree of scalability, since it is able to optimize the memory consumption / execution time ratio for different applications and data by using featur ..."
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Cited by 1 (1 self)
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Abstract. This work introduces a scalable topological data structure for manifold triangular meshes called Compact Half–Edge (CHE). It provides a high degree of scalability, since it is able to optimize the memory consumption / execution time ratio for different applications and data by using features of its different levels. An object–oriented API using class inheritance and virtual instantiation enables a unique interface for each function at any level. CHE requires very few memory, is simple to implement and easy to use, since it substitutes pointers by container of integers and basic bitwise rules.
A Topologically-based Framework for Three-dimensional Basin Modeling
"... Three-dimensional basin-wide simulation of generation, migration and accumulation of hydrocarbons has vast potential as an uncertainty and risk assessment tool in petroleum exploration. In order to fulfill this potential, several challenges have to be addressed including the modeling of the evolutio ..."
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Cited by 1 (1 self)
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Three-dimensional basin-wide simulation of generation, migration and accumulation of hydrocarbons has vast potential as an uncertainty and risk assessment tool in petroleum exploration. In order to fulfill this potential, several challenges have to be addressed including the modeling of the evolution of complex geological structures such as salt diapirs and fault motion. In this paper, we describe a novel architecture that we have designed and implemented which specifically addresses technical challenges such as 3-D representation of geological models, meshing, parallel computing, and visualization of the massive amount of data involved in these simulations. The core of this architecture is a 3-D topological framework for the representation of evolving geological structures that enables numerical simulation of geological processes undergoing large deformations within sedimentary basin and lithosphere. In this framework, the topology (or informally, connectivity) is separated from the geometry of the geological models, making it possible to update the geometry without altering the model topology. A mesh is treated as a possible realization of the geometric model and hence as an attribute of the topology. This architecture greatly simplifies the automatic meshing and re-meshing associated with large deformations such as those associated with the formation and evolution of salt diapirs. In addition, this architecture was designed to consider the geometry of geological elements in the partitioning of the computational domain and, thus, it is suitable to the solution of the partial differential equations in parallel. This is beneficial because of the large computational resources required to solve numerically the equations governing heat and fluid transport processes within sediments.
3D triangulations for . . .
"... This paper presents a methodology for creating 3D non-structured meshes for industrial applications, which honor all the boundaries of the domain. The input for the system is a multi-region 3D non-manifold model, possibly containing dangling faces, which poses a number of difficulties for standard ..."
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This paper presents a methodology for creating 3D non-structured meshes for industrial applications, which honor all the boundaries of the domain. The input for the system is a multi-region 3D non-manifold model, possibly containing dangling faces, which poses a number of difficulties for standard 3D triangulation frameworks. The main contribution of this work consists of a detailed description of how these difficulties were overcome in a real implementation.
