{"title":"Associativity between feature models across domains","authors":"S. Subramani, B. Gurumoorthy","doi":"10.1145/781606.781658","DOIUrl":"https://doi.org/10.1145/781606.781658","url":null,"abstract":"Associativity between feature models implies the automatic updating of different feature models of a part after changes are made in one of its feature models. This is an important requirement in a distributed and concurrent design environment, where integrity of part geometry has to be maintained through changes made in different task domains.The proposed algorithm takes multiple feature models of a part as input and modifies other feature models to reflect the changes made to a feature in a feature model. The proposed algorithm updates feature volumes in a model that has not been edited and then classifies the updated volumes to obtain the updated feature model. The spatial arrangement of feature faces and adjacency relationship between features are used to isolate features in a view that are affected by the modification. Feature volumes are updated based on the classification of the feature volume of the modified feature with respect to feature volumes of the model being updated. The algorithm is capable of handling all types of feature modifications namely, feature deletion, feature creation, and changes to feature location and parameters. In contrast to current art in automatic updating of feature models, the proposed algorithm does not use an intermediate representation, does not re-interpret the feature model from a low level representation and handles interacting features. Results of implementation on typical cases are presented.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123820626","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}
{"title":"Feature preserved volume simplification","authors":"Wei Hong, A. Kaufman","doi":"10.1145/781606.781661","DOIUrl":"https://doi.org/10.1145/781606.781661","url":null,"abstract":"The goal of this work is to simplify volumetric datasets while preserving the sharp boundary features and the topology of the 3D scalar field. The simplification is performed on the volumetric datasets defined as a tetrahedral mesh. The sharp boundary features are detected and preserved in the simplification to conserve the salient details of the tetrahedral mesh. The topology of the 3D scalar field is preserved by maintaining critical points extracted from the original dataset. No critical vertices are removed or generated during the simplification process. A gradient magnitude based error metric is used to estimate the error associated with a simplification step. The simplified tetrahedral mesh is rendered using a hardware-accelerated unstructured volume rendering algorithm. This method produces results which are visually similar to the original dataset.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132331796","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}
{"title":"Any open bounded subset of Rn has the same homotopy type than its medial axis","authors":"A. Lieutier","doi":"10.1145/781606.781620","DOIUrl":"https://doi.org/10.1145/781606.781620","url":null,"abstract":"Medial Axis Transform is sometimes used as an intermediate representation in algorithms for meshing or recognition of shapes from digitized data. This raises the question whether the Medial Axis captures fundamental topological invariants of the object. The (positive) answer has been known already in the case of smooth objects. The main result presented here is the homotopy equivalence of any bounded open subset of Rn with its Medial Axis.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123349567","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}
{"title":"Interactive shape design using volumetric implicit PDEs","authors":"Haixia Du","doi":"10.1145/781606.781642","DOIUrl":"https://doi.org/10.1145/781606.781642","url":null,"abstract":"Solid modeling based on Partial Differential Equations (PDEs) can potentially unify both geometric constraints and functional requirements within a single design framework to model real-world objects via its explicit, direct integration with parametric geometry. In contrast, implicit functions indirectly define geometric objects as the level-set of underlying scalar fields. To maximize the modeling potential of PDE-based methodology, in this paper we tightly couple PDEs with volumetric implicit functions in order to achieve interactive, intuitive shape representation, manipulation, and deformation. In particular, the unified approach can reconstruct the PDE geometry of arbitrary topology from scattered data points or a set of sketch curves. We make use of a fourth-order elliptic PDE to define the volumetric implicit function. The proposed implicit PDE model has the capability to reconstruct a complete solid model from partial information and facilitates the direct manipulation of underlying volumetric datasets via sketch curves, iso-surface sculpting, deformation of arbitrary interior regions, as well as a set of CSG operations inside the working space.The prototype system that we have developed allows designers to interactively sketch the curve outlines of the object, define intensity values and gradient directions, and specify interpolatory points in the 3D working space. The governing implicit PDE treats these constraints as generalized boundary conditions to determine the unknown scalar intensity values over the entire working space. The implicit shape is reconstructed with specified intensity value accordingly and can be deformed using a set of sculpting toolkits. We use the finite-difference discretization and variational interpolating approach with the localized iterative solver for the numerical integration of our PDEs in order to accommodate the diversity of generalized boundary constraints.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128094225","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}
{"title":"Constrained modifications of non-manifold B-reps","authors":"G. Caumon, C. Sword, J. Mallet","doi":"10.1145/781606.781657","DOIUrl":"https://doi.org/10.1145/781606.781657","url":null,"abstract":"Non-manifold boundary representations (b-reps) are increasingly used in Geosciences for a variety of applications (3D geographical information systems, basin modeling, geophysical processing, etc.). Meanwhile, the uncertainties associated with subsurface data make it desirable to modify such models efficiently.We present a method to deform locally a surface in a triangulated b-rep while maintaining a constant number of spatial regions in the model. This method does not require completely rebuilding the model, and thus allows efficient and robust updates of the model definition.The method requires that the reshaped surface does not intersect the boundaries of its adjoining regions, which can be checked using existing collision detection algorithms. Also, the non-manifold contacts must be updated after the modification, and the triangles must be altered, to maintain sealed regions.For this, we propose to parameterize locally the surfaces that the modified surface moves along. This parametric space is used to 1) constrain the displacement of the deformed surface border and, 2) re-triangulate in the plane the neighboring surfaces around the modified contacts. The method, tested in the context of an interactive graphical manipulator, is very efficient and independent from the deformation mechanism.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128145246","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}
{"title":"3D zernike descriptors for content based shape retrieval","authors":"Marcin Novotni, R. Klein","doi":"10.1145/781606.781639","DOIUrl":"https://doi.org/10.1145/781606.781639","url":null,"abstract":"Content based 3D shape retrieval for broad domains like the World Wide Web has recently gained considerable attention in Computer Graphics community. One of the main challenges in this context is the mapping of 3D objects into compact canonical representations referred to as descriptors, which serve as search keys during the retrieval process. The descriptors should have certain desirable properties like invariance under scaling, rotation and translation. Very importantly, they should possess descriptive power providing a basis for similarity measure between three-dimensional objects which is close to the human notion of resemblance.In this paper we advocate the usage of so-called 3D Zernike invariants as descriptors for content based 3D shape retrieval. The basis polynomials of this representation facilitate computation of invariants under the above transformations. Some theoretical results have already been summarized in the past from the aspect of pattern recognition and shape analysis. We provide practical analysis of these invariants along with algorithms and computational details. Furthermore, we give a detailed discussion on influence of the algorithm parameters like type and resolution of the conversion into a volumetric function, number of utilized coefficients, etc. As is revealed by our study, the 3D Zernike descriptors are natural extensions of spherical harmonics based descriptors, which are reported to be among the most successful representations at present. We conduct a comparison of 3D Zernike descriptors against these regarding computational aspects and shape retrieval performance.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123119604","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}
{"title":"t-FFD: free-form deformation by using triangular mesh","authors":"Kazuya G. Kobayashi, K. Ootsubo","doi":"10.1145/781606.781641","DOIUrl":"https://doi.org/10.1145/781606.781641","url":null,"abstract":"A new method of free-form deformation, t-FFD, is proposed. An original shape of large-scale polygonal mesh or point-cloud is deformed by using a control mesh, which is constituted of a set of triangles with arbitrary topology and geometry, including the cases of disconnection or self-intersection. For modeling purposes, a designer can handle the shape directly or indirectly, and also locally or globally. This method works on a simple mapping mechanism. First, each point of the original shape is parametrized by the local coordinate system on each triangle of the control mesh. After modifying the control mesh, the point is mapped according to each modified triangle. Finally, the mapped locations are blended as a new position of the original point, then a smoothly deformed shape is achieved. Details of the t-FFD are discussed and examples are shown.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131149019","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}
Dmitriy Bespalov, A. Shokoufandeh, W. Regli, Wei Sun
{"title":"Scale-space representation of 3D models and topological matching","authors":"Dmitriy Bespalov, A. Shokoufandeh, W. Regli, Wei Sun","doi":"10.1145/781606.781638","DOIUrl":"https://doi.org/10.1145/781606.781638","url":null,"abstract":"Reeb graphs have been shown to be effective for topology matching of 3D objects. Their effectiveness breaks down, however, when the individual models become very geometrically and topologically detailed---as is the case for complex machined parts. The result is that Reeb graph techniques, as developed for matching general shape and computer graphics models, produce poor results when directly applied to create engineering databases.This paper presents a framework for shape matching through scale-space decomposition of 3D models. The algorithm is based on recent developments in efficient hierarchical decomposition of metric data using its spectral properties. Through spectral decomposition, we reduce the problem of matching to that of computing a mapping and distance measure between vertex-labeled rooted trees. We use a dynamic programming scheme to compute distances between trees corresponding to solid models. Empirical evaluation of the algorithm on an extensive set of 3D matching trials demonstrates both robustness and efficiency of the overall approach.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115792825","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}
{"title":"Specification of freeform features","authors":"E. V. D. Berg, H. A. V. D. Meiden, W. Bronsvoort","doi":"10.1145/781606.781618","DOIUrl":"https://doi.org/10.1145/781606.781618","url":null,"abstract":"Freeform feature modeling is an extension to feature modeling in which, in addition to regular-shaped features, also freeform features are possible. Due to the large variety of freeform features, a generic approach to specify such features is required. This paper describes such an approach. A freeform feature class is specified by using a prototype and constraints. The latter are used to define intuitive parameters and validity conditions for the class. A new, prototype-driven constraint solving method is used to unambiguously determine a freeform feature during the specification both of a class and of an instance to be added to a model. The specification of freeform features and the prototype-driven constraint solving method are discussed. Several examples are given.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122517445","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}
{"title":"Direct incremental transmission of boundary representation","authors":"Jie Li, Shuming Gao, Xun Zhou","doi":"10.1145/781606.781655","DOIUrl":"https://doi.org/10.1145/781606.781655","url":null,"abstract":"The real-time transmission of the boundary representation (B-rep) is necessitated by collaborative design. However, it is difficult since the B-rep is very complex and the current network bandwidth is limited. Incremental transmission, which can significantly decrease the data to be delivered, makes it possible to transmit the B-rep in real time during collaborative design.In this paper, we propose an approach to direct incremental transmission of the B-rep over Internet. The algorithm consists of three steps: Identify and encode the incremental model of the B-rep once a modeling operation is performed; Then, transmit the incremental model as well as the related geometric information to other remote site; Finally, decode the received codes of incremental model and directly embed the restored entities into the local B-rep. The traits of the approach lie in: (a) The incremental B-rep is identified, transmitted and restored completely based on the B-rep data structure without the support of any other auxiliary model; (b) Topological entity hierarchy chain is put forward to enable the simple and direct recovery of the transmitted incremental B-rep.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130576065","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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