Computer-Aided Design最新文献_第2页

Minimal surface-guided higher-order mesh generation for CAD models 为 CAD 模型生成最小曲面引导的高阶网格

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-10-01 DOI: 10.1016/j.cad.2024.103810

Kaixin Yu , Bohan Wang , Xuejuan Chen , Ying He , Jianjun Chen

引用次数: 0

Boundary recognition of ship planar components from point clouds based on trimmed delaunay triangulation 基于修剪三角测量法的点云船舶平面部件边界识别

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-09-27 DOI: 10.1016/j.cad.2024.103808

Puhao Lei , Zhen Chen , Runli Tao , Jun Li , Yuchi Hao

{"title":"Boundary recognition of ship planar components from point clouds based on trimmed delaunay triangulation","authors":"Puhao Lei , Zhen Chen , Runli Tao , Jun Li , Yuchi Hao","doi":"10.1016/j.cad.2024.103808","DOIUrl":"10.1016/j.cad.2024.103808","url":null,"abstract":"<div><div>A vision-based boundary detector is crucial for intelligent processing of ship planar components due to its automatically identifying workpiece edges. However, traditional methods suffer from many issues such as low accuracy and excessive detection errors for these workpieces with complex shape profiles. This paper proposes a trimmed Delaunay triangulation method (TDT) for recognizing boundary edges of planar workpieces from point clouds. It begins by distinguishing the difference of binary image pixel generated from point cloud to eliminate redundant points far away from plane boundary. Then, a triangulation trimming algorithm is developed to extract the edge points from the simplified points. Finally, complete plane boundary is reconstructed by a clustering-and-fitting method from the extracted edge points. Experimental results from multiple angles show that average absolute errors of straight edges and angles recognition are 1.29 mm and 1.04° respectively, which demonstrate that TDT has a high identification accuracy and robustness of plane boundary edge.</div></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"178 ","pages":"Article 103808"},"PeriodicalIF":3.0,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

eCAD-Net: Editable Parametric CAD Models Reconstruction from Dumb B-Rep Models Using Deep Neural Networks eCAD-Net：利用深度神经网络从呆板的 B-Rep 模型重建可编辑的参数化 CAD 模型

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-09-24 DOI: 10.1016/j.cad.2024.103806

Chao Zhang , Arnaud Polette , Romain Pinquié , Gregorio Carasi , Henri De Charnace , Jean-Philippe Pernot

引用次数: 0

Numerical integration on 2D/3D arbitrary domains: Adaptive quadrature/cubature rule for domains with curved boundaries 二维/三维任意域的数值积分：具有弯曲边界的域的自适应正交/余角规则

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-09-24 DOI: 10.1016/j.cad.2024.103807

Nafiseh Niknejadi, Bijan Boroomand

{"title":"Numerical integration on 2D/3D arbitrary domains: Adaptive quadrature/cubature rule for domains with curved boundaries","authors":"Nafiseh Niknejadi, Bijan Boroomand","doi":"10.1016/j.cad.2024.103807","DOIUrl":"10.1016/j.cad.2024.103807","url":null,"abstract":"<div><div>This paper introduces an efficient quadrature rule for domains with curved boundaries in 2D/3D. Building upon our previous work focused on polytopes (Comput. Methods Appl. Mech. Engrg. 403 (2023) 115,726), we extend this method to handle volume/boundary integration on domains with general configurations and boundaries. In this method, we approximate a generic function using a finite number of orthogonal polynomials, and we obtain the coefficients of these polynomials through the integration points. The physical domain is enclosed by a fictitious rectangular/cuboidal domain, where a tensor-product of Gauss quadrature points is primarily considered. To locate the integration points that are strictly within the domain under consideration (e.g., the physical 3D domain itself or its mapped boundaries), we form a system of algebraic equations whose dimensions depend solely on the number of polynomials, not the number of quadrature points which may be significantly larger. This allows us to construct a full-rank square coefficient matrix, leading to the uniqueness of the solution, and the system of equations is then solved through a straightforward inverse process. To evaluate the integral of the polynomials, we transform the integration over the domain under consideration into an equivalent integration along the domain's boundaries using the divergence theorem. For 2D cases, we perform the boundary integration using Gauss points along the curved lines. In 3D cases, we provide an efficient algorithm for computing the boundary integrals over curved surfaces. We present several integration problems involving two and three-dimensional curved regions to demonstrate the accuracy and efficiency of the proposed method.</div></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"178 ","pages":"Article 103807"},"PeriodicalIF":3.0,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multi-part kinematic constraint prediction for automatic generation of CAD model assemblies using graph convolutional networks 利用图卷积网络自动生成 CAD 模型装配的多部分运动学约束预测

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-09-21 DOI: 10.1016/j.cad.2024.103805

Lucas Vergez, Arnaud Polette, Jean-Philippe Pernot

{"title":"Multi-part kinematic constraint prediction for automatic generation of CAD model assemblies using graph convolutional networks","authors":"Lucas Vergez, Arnaud Polette, Jean-Philippe Pernot","doi":"10.1016/j.cad.2024.103805","DOIUrl":"10.1016/j.cad.2024.103805","url":null,"abstract":"<div><div>This paper presents a machine learning-based approach to predict kinematic constraints between CAD models that have potentially never been assembled together before. During the learning phase, the algorithm is trained to predict the next-possible-constraints between a set of parts candidate to the assembly. Assemblies are represented in a new graph-based formalism that is capable of capturing features associated with parts, interfaces between parts and constraints between them. Using such a multi-level feature extraction strategy coupled to a state-by-state graph decomposition, the approach does not need to be trained on a large database. This formalism is used to model both the network input and output where the next-possible-constraints appear after evaluation. The core of the approach relies on a series of networks based on a link-prediction encoder–decoder architecture, integrating the capabilities of several convolutional networks trained in an end-to-end manner. A decision-making algorithm is added to post-process the output and drive the prediction process in finding one among the set of next-possible-constraints. This process is repeated until no more constraints can be added. The experimental results show that the proposed approach outperforms state-of-the-art methods on such assembly tasks. Although the state-by-state assembly algorithm is iterative, it still takes into account the whole set of parts as well as the whole set of constraints already predicted, and this makes it possible to handle constraint cycles, which is generally not possible when not considering multiple parts as input.</div></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"178 ","pages":"Article 103805"},"PeriodicalIF":3.0,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Efficient evaluation of Bernstein-Bézier coefficients of B-spline basis functions over one knot span 在一个节点跨度上高效评估 B-样条曲线基函数的伯恩斯坦-贝塞尔系数

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-09-19 DOI: 10.1016/j.cad.2024.103804

Filip Chudy, Paweł Woźny

引用次数: 0

Computational design of asymptotic geodesic hybrid gridshells via propagation algorithms 通过传播算法计算设计渐近大地混合网格壳

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-09-12 DOI: 10.1016/j.cad.2024.103800

Bolun Wang , Maryam Almaskin , Helmut Pottmann

{"title":"Computational design of asymptotic geodesic hybrid gridshells via propagation algorithms","authors":"Bolun Wang , Maryam Almaskin , Helmut Pottmann","doi":"10.1016/j.cad.2024.103800","DOIUrl":"10.1016/j.cad.2024.103800","url":null,"abstract":"<div><p>Complex architectural structures may be built in a simple and cost-effective way if their geometry respects the fabrication constraints. Examples of such structures are provided by gridshells that are built from straight and flat slats which are bent on site so that they become tangential or normal to the design surface. Tangential slats follow geodesic curves on the surface, while normal slats are attached along asymptotic curves. Extending work by Frei Otto, Julius Natterer and others, who placed the slats tangentially, Eike Schling proposed structures which also contain slats normal to the reference surface. In the present paper we address those gridshells that consist of three families of bent elements, either tangential or normal to the design surface, and are arranged in a triangular web. We propose algorithms for the computational design of such webs that start from a boundary strip and propagate it, partially under additional guidance, to an entire web.</p></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"178 ","pages":"Article 103800"},"PeriodicalIF":3.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010448524001271/pdfft?md5=c5c09a93ed9e03bddcee7eeb1f245a5d&pid=1-s2.0-S0010448524001271-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Point containment algorithms for constructive solid geometry with unbounded primitives 无界基元构造实体几何的点包含算法

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-09-11 DOI: 10.1016/j.cad.2024.103803

Paul K. Romano , Patrick A. Myers , Seth R. Johnson , Aljaz̆ Kols̆ek , Patrick C. Shriwise

{"title":"Point containment algorithms for constructive solid geometry with unbounded primitives","authors":"Paul K. Romano , Patrick A. Myers , Seth R. Johnson , Aljaz̆ Kols̆ek , Patrick C. Shriwise","doi":"10.1016/j.cad.2024.103803","DOIUrl":"10.1016/j.cad.2024.103803","url":null,"abstract":"<div><p>We present several algorithms for evaluating point containment in constructive solid geometry (CSG) trees with unbounded primitives. Three algorithms are presented based on postfix, prefix, and infix notations of the CSG binary expression tree. We show that prefix and infix notations enable short-circuiting logic, which reduces the number of primitives that must be checked during point containment. To evaluate the performance of the algorithms, each algorithm was implemented in the OpenMC Monte Carlo particle transport code, which relies on CSG to represent solid bodies through which subatomic particles travel. Two sets of tests were carried out. First, the execution time to generate a rasterized image of a 2D slice of three CSG models of varying complexity was measured. Use of both prefix and infix notations offered significant speedup over the postfix notation that has traditionally been used in particle transport codes, with infix resulting in a 6<span><math><mo>×</mo></math></span> reduction in execution time relative to postfix for a model of a tokamak fusion device. We then measured the execution time of neutron transport simulations of the same three models using each of the algorithms. The results and performance improvements reveal the same trends as for the rasterization test, with a 5.52<span><math><mo>×</mo></math></span> overall speedup using the infix notation relative to the original postfix notation in OpenMC for the tokamak model.</p></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"178 ","pages":"Article 103803"},"PeriodicalIF":3.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010448524001301/pdfft?md5=8fddc42a59401cae480fb7d7905061a3&pid=1-s2.0-S0010448524001301-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tessellation and interactive visualization of four-dimensional spacetime geometries 四维时空几何图形的细分和交互式可视化

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-08-24 DOI: 10.1016/j.cad.2024.103792

Philip Claude Caplan

{"title":"Tessellation and interactive visualization of four-dimensional spacetime geometries","authors":"Philip Claude Caplan","doi":"10.1016/j.cad.2024.103792","DOIUrl":"10.1016/j.cad.2024.103792","url":null,"abstract":"<div><p>This paper addresses two problems needed to support four-dimensional (<span><math><mrow><mn>3</mn><mi>d</mi><mo>+</mo><mi>t</mi></mrow></math></span>) spacetime numerical simulations. The first contribution is a general algorithm for producing conforming spacetime meshes of moving geometries. Here, the surface points of the geometry are embedded in a four-dimensional space as the geometry moves in time. The geometry is first tessellated at prescribed time steps and then these tessellations are connected in the parameter space of each geometry entity to form tetrahedra. In contrast to previous work, this approach allows the resolution of the geometry to be controlled at each time step. The only restriction on the algorithm is the requirement that no topological changes to the geometry are made (i.e. the hierarchical relations between all geometry entities are maintained) as the geometry moves in time. The validity of the final mesh topology is verified by ensuring the tetrahedralizations represent a closed 3-manifold. For some analytic problems, the <span><math><mrow><mn>4</mn><mi>d</mi></mrow></math></span> volume of the tetrahedralization is also verified. The second problem addressed in this paper is the design of a system to interactively visualize four-dimensional meshes when the <span><math><mrow><mn>4</mn><mi>d</mi></mrow></math></span> view changes, including tetrahedra (embedded in <span><math><mrow><mn>4</mn><mi>d</mi></mrow></math></span>) and pentatopes. Algorithms that either include or exclude a geometry shader are described, and the efficiency of each approach is then compared. Overall, the results suggest that visualizing tetrahedra (either those bounding the domain, or extracted from a pentatopal mesh) using a geometry shader achieves the highest frame rate, realizing interactive frame rates of at least 15 frames per second for meshes with about 50 million tetrahedra.</p></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"178 ","pages":"Article 103792"},"PeriodicalIF":3.0,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010448524001192/pdfft?md5=e51e1de5cf978ffc80f6145b0ad55e2e&pid=1-s2.0-S0010448524001192-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142117737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Topology-aware blending method for implicit heterogeneous porous model design 用于隐式异质多孔模型设计的拓扑感知混合法

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-08-08 DOI: 10.1016/j.cad.2024.103782

Depeng Gao, Yang Gao, Yuanzhi Zhang, Hongwei Lin

{"title":"Topology-aware blending method for implicit heterogeneous porous model design","authors":"Depeng Gao, Yang Gao, Yuanzhi Zhang, Hongwei Lin","doi":"10.1016/j.cad.2024.103782","DOIUrl":"10.1016/j.cad.2024.103782","url":null,"abstract":"<div><p>Porous structures are materials consisting of minuscule pores, where the microstructure morphology significantly impacts their macroscopic properties. Integrating different porous structures through a blending method is indispensable to cater to diverse functional regions in heterogeneous models. Previous studies on blending methods for porous structures have mainly focused on controlling the shape of blending regions, yet they have fallen short in effectively addressing topological errors in blended structures. This paper introduces a new blending method that successfully addresses this issue. Initially, a novel initialization method is proposed, which includes distinct strategies for blending regions of varying complexities. Subsequently, we formulate the challenge of eliminating topological errors as an optimization problem based on persistent homology. Through iterative updates of control coefficients, this optimization problem is solved to generate a blended porous structure. Our approach not only avoids topological errors but also governs the shape and positioning of the blending region while remaining unchanged in the structure outside blending region. The experimental outcomes validate the effectiveness of our method in producing high-quality blended porous structures. Furthermore, these results highlight potential applications of our blending method in biomimetics and the design of high-stiffness mechanical heterogeneous models.</p></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"177 ","pages":"Article 103782"},"PeriodicalIF":3.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141993065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0