International Conference on Smart Media and Applications最新文献_第5页

The swept surface of an elliptic cylinder 椭圆圆柱的扫面

International Conference on Smart Media and Applications Pub Date : 2001-05-01 DOI: 10.1145/376957.376992

Stephen Mann, S. Bedi, D. Roth

{"title":"The swept surface of an elliptic cylinder","authors":"Stephen Mann, S. Bedi, D. Roth","doi":"10.1145/376957.376992","DOIUrl":"https://doi.org/10.1145/376957.376992","url":null,"abstract":"In this poster, we present a method for computing a piecewise linear approximation to the surface swept by a moving rotating elliptic cylinder. Our method is a generalization of the imprint point method we developed for computing points on a surface of revolution [1]. The method is based on on identifying grazing points on the surface of revolution at a sequence of positions, and for each position connecting the grazing points with a piecewise linear curve. A collection of grazing curves is joined to approximate the swept surface and stitched into a solid model. Previously this method has been tested on cylinders, toruses, and cones.\u0000We reduce the problem of finding grazing points on the elliptic cylinder to that of finding points on an ellipse by slicing the elliptic cylinder with planes perpendicular to the tool axis. The method for finding the grazing points an a circular slice of a surface of revolution works because the normals to the surface along each circle pass through the axis of revolution. This allowed us to express the direction of motion of a point on the surface as the sum of the motion of a point on the axis plus a rotation around that point on the axis.\u0000This simple method for finding grazing points fails for an elliptic cylinder because the normals of a slice of the elliptic cylinder do not pass through center of ellipse. Worse, in the case of a twisted cylinder, the normals to the surface do not lie in the plane of the elliptical slice. However, these problems are readily resolved by setting up a small system of equations that we can solve for the grazing points on an elliptic slice. We begin by solving the problem for the elliptic cylinder, after which we will show how to generalize the solution to the twisted elliptic cylinder.","PeriodicalId":286112,"journal":{"name":"International Conference on Smart Media and Applications","volume":"252 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134271923","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}

引用次数: 0

Max-fit biarc fitting to STL models for rapid prototyping processes STL模型的最大拟合双弧拟合，用于快速原型制作过程

International Conference on Smart Media and Applications Pub Date : 2001-05-01 DOI: 10.1145/376957.376983

B. Koç, Yuan-Shin Lee, Yawei Ma

引用次数: 4

The ellipsoidal skeleton in medical applications 椭球骨架在医学上的应用

International Conference on Smart Media and Applications Pub Date : 2001-05-01 DOI: 10.1145/376957.376961

F. Banégas, M. Jaeger, D. Michelucci, Marc Roelens

引用次数: 30

Construction of fair surfaces over irregular meshes 在不规则网格上构建公平的表面

International Conference on Smart Media and Applications Pub Date : 2001-05-01 DOI: 10.1145/376957.376969

G. Westgaard, H. Nowacki

{"title":"Construction of fair surfaces over irregular meshes","authors":"G. Westgaard, H. Nowacki","doi":"10.1145/376957.376969","DOIUrl":"https://doi.org/10.1145/376957.376969","url":null,"abstract":"This paper describes the process of constructing a fair, open or closed C1 surface over a given irregular curve mesh. The input to the surface construction consists of point and/or curve data which are individually marked to be interpolated or approximated and are arranged according to an arbitrary irregular curve mesh topology. The surface constructed from these data will minimize flexibly chosen fairness criteria. The set of available fairness criteria is able to measure surface characteristics related to curvature, variation of curvature and higher order surface derivatives based on integral functionals of quadratic form derived from the second, third and higher order parametric derivatives of the surface. The choice is based on the desired shape character.\u0000The construction of the surface begins with a midpoint refinement decomposition of the irregular mesh into aggregates of patch complexes in which the only remaining type of building block is the quadrilateral Bézier patch of degrees 4 by 4. The fairing process may be applied regionally or to the entire surface. The fair surface is built up either in a single global step or iteratively in a three stage local process, successively accounting for vertex, edge curve and patch interior continuity and fairness requirements.\u0000This surface fairing process will be illustrated by two main examples, a benchmark test performed on a topological cube, resulting in many varieties of fair shapes for a closed body, and a practical application to a ship hull surface for a modern container ship, which is subdivided into several local fairing regions with suitable transition pieces. The examples will demonstrate the capability of the fairing approach of contending with irregular mesh topologies, dealing with multiple regions, applying global and local fairing processes and will illustrate the influence of the choice of criteria upon the character of the resulting shapes.","PeriodicalId":286112,"journal":{"name":"International Conference on Smart Media and Applications","volume":"1022 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123120352","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}

引用次数: 30

Database techniques for archival of solid models 实体模型存档的数据库技术

International Conference on Smart Media and Applications Pub Date : 2001-05-01 DOI: 10.1145/376957.376968

David T. McWherter, Mitchell Peabody, A. Shokoufandeh, W. Regli

{"title":"Database techniques for archival of solid models","authors":"David T. McWherter, Mitchell Peabody, A. Shokoufandeh, W. Regli","doi":"10.1145/376957.376968","DOIUrl":"https://doi.org/10.1145/376957.376968","url":null,"abstract":"This paper presents techniques for managing solid models in modern relational database management systems. Our goal is to enable support for traditional database operations (sorting, distance metrics, range queries, nearest neighbors, etc) on large databases of solid models. As part of this research, we have developed a number of novel storage and retrieval strategies that extend the state-of-the-art in database research as well as change the way in which solid modeling software developers and design and manufacturing enterprises view CAD-centric data management problems.\u0000Past research and current commercial systems for engineering information management and Product Data Management (PDM) have predominantly taken annotation and document-based approaches—where the solid modeling data itself is simply stored as a related file to other project documents. Research in CAD and engineering databases has produced great advances, such as representation schemas for STEP-based data elements, however existing technologies stop short of enabling content-based and semantic retrieval of solid modeling data of the types now available for other higher-dimensional media (images, audio and video).\u0000Our approach encodes solid model BRep information as a Model Signature Graph. We demonstrate how Model Signature Graphs can be used for topological similarity assessment of solid models and enable clustering for data mining of a large design repositories. We believe this work will begin to bridge the solid modeling and database communities, enabling new paradigms for interrogation of CAD datasets.","PeriodicalId":286112,"journal":{"name":"International Conference on Smart Media and Applications","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126992413","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}

引用次数: 65

The power crust 权力外壳

International Conference on Smart Media and Applications Pub Date : 2001-05-01 DOI: 10.1145/376957.376986

N. Amenta, Sunghee Choi, R. Kolluri

{"title":"The power crust","authors":"N. Amenta, Sunghee Choi, R. Kolluri","doi":"10.1145/376957.376986","DOIUrl":"https://doi.org/10.1145/376957.376986","url":null,"abstract":"The power crust is a construction which takes a sample of points from the surface of a three-dimensional object and produces a surface mesh and an approximate medial axis. The approach is to first approximate the medial axis transform (MAT) of the object. We then use an inverse transform to produce the surface representation from the MAT.\u0000This idea leads to a simple algorithm with theoretical guarantees comparable to those of other surface reconstruction and medial axis approximation algorithms. It also comes with a guarantee that does not depend in any way on the quality of the input point sample. Any input gives an output surface which is the `watertight' boundary of a three-dimensional polyhedral solid: the solid described by the approximate MAT. This unconditional guarantee makes the algorithm quite robust and eliminates the polygonalization, hole-filling or manifold extraction post-processing steps required in previous surface reconstruction algorithms.\u0000In this paper, we use the theory to develop a power crust implementation which is indeed robust for realistic and even difficult samples. We describe the careful design of a key subroutine which labels parts of the MAT as inside or outside of the object, easy in theory but non-trivial in practice. We find that we can handle areas in which the input sampling is scanty or noisy by simply discarding the unreliable parts of the MAT approximation. We demonstrate good empirical results on inputs including models with sharp corners, sparse and unevenly distributed point samples, holes, and noise, both natural and synthetic.\u0000We also demonstrate some simple extensions: intentionally leaving holes where there is no data, producing approximate offset surfaces, and simplifying the approximate MAT in a principled way to preserve stable features.","PeriodicalId":286112,"journal":{"name":"International Conference on Smart Media and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129173265","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}

引用次数: 919

Parallel processing for 2-1/2D machining simulation 2-1/2D加工仿真的并行处理

International Conference on Smart Media and Applications Pub Date : 2001-05-01 DOI: 10.1145/376957.376974

A. Spence, Z. Li

{"title":"Parallel processing for 2-1/2D machining simulation","authors":"A. Spence, Z. Li","doi":"10.1145/376957.376974","DOIUrl":"https://doi.org/10.1145/376957.376974","url":null,"abstract":"Continued progress in the area of solid modeler based machining process simulation is hindered by the complexity growth that occurs for a large number of tool paths n. For this reason, many researchers have adopted the Z-buffer approach. Boundary-representation (B-rep), however, remains the dominant choice for commercial modelers. This paper begins by reviewing the current state of solid modeler based machining simulation. Using an industrial example, the growth rate, for a simple feed rate scheduling application, is estimated to be O(n1.5). It is shown that round robin parallel scheduling quickly becomes inefficient due to the fraction of time spent on tool swept volume Boolean subtractions. The tool path sequence is next heuristically subdivided into nearly equal size neighbor groups. Only the Boolean subtractions required for accurate simulation are included in the group. Each group is then simulated in parallel, achieving a greatly reduced wall clock running time. Computational geometry methods are described that permit rapid identification of tool path neighbors. It is shown that, under practical assumptions, the total number of tool path neighbor pairs is O(n), justifying the benefit of parallel processing. Both dual CPU and networked parallel solutions are implemented. Geometric images and running time plots are included to illustrate. Discussion is included, with proposed steps to further reduce calculation time.","PeriodicalId":286112,"journal":{"name":"International Conference on Smart Media and Applications","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130424037","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}

引用次数: 17

Out-of-core build of a topological data structure from polygon soup 基于多边形汤的拓扑数据结构的核外构建

International Conference on Smart Media and Applications Pub Date : 2001-05-01 DOI: 10.1145/376957.376977

Sara McMains, J. Hellerstein, C. Séquin

引用次数: 24

FEM-based subdivision solids for dynamic and haptic interaction 基于有限元的动态和触觉交互细分固体

International Conference on Smart Media and Applications Pub Date : 2001-05-01 DOI: 10.1145/376957.376998

K. T. McDonnell, Hong Qin

引用次数: 13

Finding approximate shape regularities in reverse engineered solid models bounded by simple surfaces 在以简单曲面为界的逆向工程实体模型中寻找近似形状规律

International Conference on Smart Media and Applications Pub Date : 2001-05-01 DOI: 10.1145/376957.376981

F. Langbein, B. Mills, A. Marshall, Ralph Robert Martin

{"title":"Finding approximate shape regularities in reverse engineered solid models bounded by simple surfaces","authors":"F. Langbein, B. Mills, A. Marshall, Ralph Robert Martin","doi":"10.1145/376957.376981","DOIUrl":"https://doi.org/10.1145/376957.376981","url":null,"abstract":"Current reverse engineering systems are able to generate simple valid boundary representation (B-rep) models from 3D range data. Such models suffer from various inaccuracies caused by noise in the input data and algorithms. The quality of reverse engineered geometric models can potentially be improved by finding candidate shape regularities in such an initial model, and imposing a suitable subset of them on the model by using constraints, in a postprocessing step called beautification. Finding such candidate regularities is a necessary first step, and is discussed in this paper. Algorithms for analysis are presented which use feature objects to describe properties of faces, edges and vertices, and small groups of these elements in a B-rep model with only planar, spherical, cylindrical, conical and toroidal faces. The methods seek similarities between feature objects, e.g. axes which are parallel, for each property type. For each group of similar feature objects they also try to find a special feature object which might represent the group, e.g. an integer value which approximates the radius of similar cylinders. The feature objects used represent shape parameters, directions, axes and positions present in the model. Experiments show that the regularities found by these algorithms include the desired regularities. Although other spurious regularities which must be discarded in subsequent beautification steps are also produced, their number can be reduced by appropriate choice of tolerance values.","PeriodicalId":286112,"journal":{"name":"International Conference on Smart Media and Applications","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133130494","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}

引用次数: 24