ACM Symposium on Solid Modeling and Applications最新文献

{"title":"Integrated feature-based and geometric CAD data exchange","authors":"S. Spitz, A. Rappoport","doi":"10.2312/SM.20041389","DOIUrl":"https://doi.org/10.2312/SM.20041389","url":null,"abstract":"Data exchange between CAD systems is an extremely important solid modeling concept, fundamental both for the theory of the field and for its practical applications. The two main data exchange (DE) paradigms are geometric and parametric DE. Geometric DE is the ordinary method, in which the boundary representation of the object is exchanged. Parametric (or feature-based) DE is a novel method where, given a parametric history (feature) graph in a source system, the goal is to construct a graph in the target system that results in similar geometry while preserving as much parametric information as possible. Each method has its uses and associated problems.In this paper, we introduce Geometry Per Feature (GPF), a method for integration of parametric and geometric data exchange at the single part (object) level. Features can be exchanged either parametrically or geometrically, according to user guidelines and system constraints. At the target system, the resulting model is represented using a history tree, regardless of the amount of original parametric features that have been rewritten as geometric ones. Using this method we maximize the exchange of overall parametric data and overcome one of the main stumbling blocks for feature-based data exchange.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"214 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132470891","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":"Tracing surface intersections with validated ODE system solver","authors":"H. Mukundan, K. Ko, T. Maekawa, T. Sakkalis, N. Patrikalakis","doi":"10.2312/SM.20041397","DOIUrl":"https://doi.org/10.2312/SM.20041397","url":null,"abstract":"This paper presents a robust method for tracing intersection curve segments between continuous rational parametric surfaces, typically rational polynomial parametric surface patches. The tracing procedure is based on a validated ordinary differential equation (ODE) system solver which can be applied, without substantial overhead, for transversal as well as tangential intersections. Application of the validated ODE solver in the context of eliminating the phenomenon of straying and looping is discussed. In addition, we develop a method to fulfill the condition of a continuous gap-free boundary with a definite numerically verified upper bound for the intersection curve error in parameter space and is further mapped to an upper bound for the intersection curve error in 3D model space, which assists in defining well-formed boundary representation models of complex 3D solids.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115790626","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":"B-rep SE: simplicially enhanced boundary representation","authors":"Michael Freytag, V. Shapiro","doi":"10.2312/SM.20041386","DOIUrl":"https://doi.org/10.2312/SM.20041386","url":null,"abstract":"Boundary representation (B-rep) is a popular representation scheme for mechanical objects due to its ability to accurately represent piecewise smooth surfaces bounding solids. However, non-trivial topology and geometry of the surface patches hinder point generation, classification, searching, and other algorithms. We propose a new hybrid representation that addresses these shortcomings by imposing on the boundary representation an additional simplicial structure. The simplicial structure applies a triangle-mesh metaphor to the usual boundary representation, allowing access to points on the exact solid boundary or its many approximations. The resulting simplicially enhanced boundary representation (B-rep SE) simplifies and accelerates the usual boundary representation queries. We discuss full implementation of B-rep SE with the Parasolid kernel and demonstrate the advantages of B-rep SE in applications that integrate and visualize arbitrary fields on a solid's boundary.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124341963","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":"Ambient isotopic approximations for surface reconstruction and interval solids","authors":"T. Sakkalis, T. Peters","doi":"10.1145/781606.781634","DOIUrl":"https://doi.org/10.1145/781606.781634","url":null,"abstract":"Given a nonsingular compact 2-manifold <i>F</i> without boundary, we present methods for establishing a family of surfaces which can approximate <i>F</i> so that each approximant is ambient isotopic to <i>F</i>. The current state of the art in surface reconstruction is that both theory and practice are limited to generating a piecewise linear (PL) approximation. The methods presented here offer broader theoretical guidance for a rich class of ambient isotopic approximations. They are also used to establish sufficient conditions for an interval solid to be ambient isotopic to the solid it is approximating.The methods are based on <i>global</i> theoretical considerations and are compared to existing <i>local</i> methods. Practical implications of these methods are also presented. For the global case, a differential surface analysis is performed to find a positive number <i>ρ</i> so that the offsets <i>F_o(± ρ)</i> of <i>F</i> at distances <i>± ρ</i> are nonsingular. In doing so, a normal tubular neighborhood, <i>F(ρ)</i>, of <i>F</i> is constructed. Then, each approximant of <i>F</i> lies inside <i>F(ρ)</i>. Comparisons between these global and local constraints are given.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"81 3 Suppl 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":"116398632","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":"Free-form deformations via sketching and manipulating scalar fields","authors":"Jing Hua, Hong Qin","doi":"10.1145/781606.781660","DOIUrl":"https://doi.org/10.1145/781606.781660","url":null,"abstract":"This paper presents a novel Scalar-field based Free-Form Deformation (SFFD) technique founded upon general flow constraints and implicit functions. In contrast to the traditional lattice-based FFD driven by parametric geometry and spline theory, we employ scalar fields as embedding spaces instead. Upon the deformation of the scalar field, the vertices will move accordingly, which result in free-form deformations of the embedded object. The scalar field construction, sketching, and manipulation are both natural and intuitive. By tightly coupling self-adaptive subdivision and mesh optimization with SFFD, versatile multi-resolution free-form deformations can be achieved because our algorithm can adaptively refine and improve the model on the fly to improve the mesh quality. We can also enforce various constraints on embedded models, which enable our technique to preserve the shape features and facilitate more sophisticated design. Our system demonstrates that SFFD is very powerful and intuitive for shape modeling. It significantly enhances traditional FFD techniques and facilitates a larger number of shape deformations.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"21 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":"134079625","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 preserving manifold mesh from an octree","authors":"K. Ashida, N. Badler","doi":"10.1145/781606.781654","DOIUrl":"https://doi.org/10.1145/781606.781654","url":null,"abstract":"We describe an algorithm to generate a manifold mesh from an octree while preserving surface features. The algorithm requires samples of a surface (coordinates) on the octree edges, along with the surface normals at those coordinates.The distinct features of the algorithm are:the output mesh is manifold,the resolution of the output mesh can be adjusted over the space with octree subdivision, andsurface features are generally preserved.A mesh generation algorithm with this combination of advantages has not been presented before.","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":"125470976","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":"Estimating the in/out function of a surface represented by points","authors":"Vinícius Mello, L. Velho, G. Taubin","doi":"10.1145/781606.781625","DOIUrl":"https://doi.org/10.1145/781606.781625","url":null,"abstract":"We present a method to estimate the in/out function of a closed surface represented by an unorganized set of data points. From the in/out function, we compute an approximation of the signed distance function to a surface M whose sampling are given by this set of points. The procedure correctly detects the interior and the exterior of M, even if M is multiply connected. The representation of the signed distance function combines the advantages of two previously known schemes, \"Implicit Simplicial Models\" and \"Adaptively Sampled Distance Fields\", incorporating new features deriving from the concept of a Binary Multitriangulation.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"12 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":"124986424","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":"Shape intrinsic fingerprints for free-form object matching","authors":"K. Ko, T. Maekawa, N. Patrikalakis, H. Masuda, Franz-Erich Wolter","doi":"10.1145/781606.781637","DOIUrl":"https://doi.org/10.1145/781606.781637","url":null,"abstract":"This paper presents matching and similarity evaluation methods between two NURBS surfaces, and their application to copyright protection of digital data representing solids or NURBS surfaces. Two methods are employed to match objects: the moment and the curvature methods. The moment method uses integral properties, i.e. the volume, the principal moments of inertia and directions, to find the rigid body transformation as well as the scaling factor. The curvature method is based on the Gaussian and the mean curvatures to establish correspondence between two objects. The matching algorithms are applied to problems of copyright protection. A suspect model is aligned to an original model through the matching methods so that similarity between two models can be assessed to determine if the suspect model contains part(s) of the original model, which may be stored in an independent repository. Three types of tests, the weak, intermediate and strong tests, are proposed for similarity assessment between two objects. The weak and intermediate tests are performed at node points obtained through shape intrinsic wireframing. The strong test relies on isolated umbilical points which can be used as fingerprints of an object for supporting an ownership claim to the original model. The three tests are organized in two decision algorithms such that they produce systematic and statistical measures for a similarity decision between two objects in a hierarchical manner. Based on the systematic and statistical evaluation of similarity, a decision can be reached whether the suspect model is an illegal copy of the original model.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"118 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":"114627165","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":"Keynote lecture: a perspective on the future of design","authors":"K. Bowcutt","doi":"10.1145/781606.781610","DOIUrl":"https://doi.org/10.1145/781606.781610","url":null,"abstract":"Hypersonic vehicles are, by necessity, highly integrated flying machines. They also have inherently high performance and economic uncertainties. Combined, these characteristics render conventional practices inadequate for designing hypersonic vehicles. As advancing technology enables more sophisticated design tools, and computer speed continues to grow exponentially, systems will be designed in an ever more integrated fashion to wring the most out of system performance and economics. Hypersonic vehicles are therefore representative of future design challenges, and will be used as an example of future trends in design practice.Improved methods of system design that account for (and even take advantage of) the highly integrated nature of hypersonic vehicles are crucial to their successful development. Some of the advanced design methods requiring maturation and integration include: a parametric geometry generation system that provides consistent high quality geometry data to all analysis disciplines; automated data transfer between analysis tools; automated execution of high-fidelity computational analysis tools; multidisciplinary design optimization (MDO) techniques; probabilistic analysis techniques; and accurate cost modeling. Also crucial is the coupling of the vehicle design/optimization system with operations/mission modeling and simulation tools. Such a link will enable designs to be optimized for system effectiveness and economics at the highest level. Successful hypersonic vehicle design is not possible without such improved, integrated methods. This presentation will focus on this vision of future system design, and will status some aspects of progress being made toward achieving this vision.Dr. Kevin G. Bowcutt is a Boeing Senior Technical Fellow and Chief Scientist of Hypersonic Design and Applications for The Boeing Company, with 21 years of experience. Kevin is an expert in hypersonic aerodynamics, propulsion integration, and vehicle design and optimization. Dr. Bowcutt pioneered the modern viscous optimized hypersonic waverider during his doctoral research at the University of Maryland. After school, Kevin served in technical leadership roles for propulsion integration on the National AeroSpace Plane (NASP) program and worked on two national teams assembled to solve key NASP technical issues. Following NASP, Kevin led a project to test scramjet engines at speeds up to 9,000 ft/sec by firing them from a light gas gun at Lawrence Livermore National Laboratory. Next, Dr. Bowcutt conceived and led the conceptual design activity for the DARPA/Boeing Affordable Rapid-Response Missile Demonstrator (ARRMD) Mach 7 waverider vehicle, applying Multidisciplinary Design Optimization techniques to dramatically improve vehicle performance. Dr. Bowcutt most recently led the design team that created the FASST two-stage-to-orbit air-breathing reusable launch vehicle concept, which has recently become architecture #6 for the NASA Next Generation Launch","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"19 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":"129458092","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":"Automating the CAD/CAE dimensional reduction process","authors":"K. Suresh","doi":"10.1145/781606.781621","DOIUrl":"https://doi.org/10.1145/781606.781621","url":null,"abstract":"Dimensional reduction is a simplification technique that eliminates one or more dimensions from a boundary value problem. It results in significant computational savings with minimal loss in accuracy. Existing dimensional reduction methods rely on a lower-dimensional geometric entity called the mid-element that is unfortunately ill defined for irregular thin solids.The main objective of this paper is to propose a new theory of 'skeletal dimensional reduction' that is superior to existing mid-element based methods in that it unambiguous and can be easily automated. The proposed method is based on a popular skeletal representation of geometry that is well defined for all thin solids. By exploiting the unique properties of a skeletal representation it is shown how boundary value problems, specifically 2-D Laplacian problems, over complex 'beam-like' solids can be systematically reduced to lower-dimensional problems over the skeleton. Further, in the special case of a regular thin solid, the skeletal reduction simplifies, as expected, into a mid-element based dimensional reduction.","PeriodicalId":405863,"journal":{"name":"ACM Symposium on Solid Modeling and Applications","volume":"31 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":"121273922","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}