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Fast Exact Booleans for Iterated CSG using Octree-Embedded BSPs Comput. Aided Des. (IF 3.156) Pub Date : 2021-02-24 Julius Nehring-Wirxel; Philip Trettner; Leif Kobbelt
We present octree-embedded BSPs, a volumetric mesh data structure suited for performing a sequence of Boolean operations (iterated CSG) efficiently. At its core, our data structure leverages a plane-based geometry representation and integer arithmetics to guarantee unconditionally robust operations. These typically present considerable performance challenges which we overcome by using custom-tailored
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Real-Time Topology Optimization in 3D via Deep Transfer Learning Comput. Aided Des. (IF 3.156) Pub Date : 2021-02-24 Mohammad Mahdi Behzadi; Horea T. Ilieş
The published literature on topology optimization has exploded over the last two decades to include methods that use shape and topological derivatives or evolutionary algorithms formulated on various geometric representations and parametrizations. One of the key challenges of all these methods is the massive computational cost associated with 3D topology optimization problems. We introduce a transfer
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Improved Dixon Resultant for Generating Signed Algebraic Level Sets and Algebraic Boolean Operations on Closed Parametric Surfaces Comput. Aided Des. (IF 3.156) Pub Date : 2021-02-11 P. Vaitheeswaran; G. Subbarayan
Complex physical problems with emerging topologies such as phase nucleation and growth during solidification or electromigration, as well as design problems such as topology optimization are commonly modeled using phase field or level set methods. However, the implicit representations of the evolving interfaces in these methods implicitize geometrical parameters such as normals and curvatures that
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Accurate Real-time CNC Curve Interpolators Based Upon Richardson Extrapolation Comput. Aided Des. (IF 3.156) Pub Date : 2021-02-12 Rida T. Farouki
Real-time CNC interpolators achieving a constant or variable feedrate V along a parametric curve r(ξ) are usually based on truncated Taylor series expansions defining the time-dependence of the curve parameter ξ. Since the feedrate should be specified as a function of a physically meaningful variable (such as time t, path arc length s, or curvature κ) rather than ξ, successive applications of the differentiation
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Extraction of Formal Manufacturing Rules from Unstructured English Text Comput. Aided Des. (IF 3.156) Pub Date : 2021-01-14 SungKu Kang; Lalit Patil; Arvind Rangarajan; Abha Moitra; Tao Jia; Dean Robinson; Farhad Ameri; Debasish Dutta
Semantics-based approaches – founded on the idea of explicitly encoding meaning separately from the data or the application code – are being applied to manufacturing, for example, to enable early manufacturability feedback. These approaches rely on formal, i.e., computer-interpretable, knowledge and rules along with the context or semantics, which facilitates the reuse and sharing of the knowledge
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Recognition of features in sheet metal parts manufactured using progressive dies Comput. Aided Des. (IF 3.156) Pub Date : 2021-01-11 Yang Yang; Srichand Hinduja; Oladele O. Owodunni; Robert Heinemann
Feature recognition is an important stage in digital manufacturing as it supports activities such as automated process planning and part re-design. This paper describes a two-stage algorithm for recognising features in sheet metal parts which are manufactured using progressive dies. Representation of the part in neutral format (STEP AP203) facilitates the first stage of this algorithm in which the
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An Overview of Procedures and Tools for Designing Nonstandard Beam-Based Compliant Mechanisms Comput. Aided Des. (IF 3.156) Pub Date : 2021-01-21 Pietro Bilancia; Giovanni Berselli
Beam-based Compliant Mechanisms (CMs) are increasingly studied and implemented in precision engineering. Straight beams with uniform cross section are the basic modules in several design concepts, which can be deemed as standard CMs. Their behavioral analysis can be addressed with a large variety of techniques, including the Euler–Bernoulli beam theory, the Pseudo-Rigid Body (PRB) method, the beam
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PolyFrame, Efficient Computation for 3D Graphic Statics Comput. Aided Des. (IF 3.156) Pub Date : 2021-01-22 Andrei Nejur; Masoud Akbarzadeh
In this paper, we introduce a structural form finding plugin called PolyFrame for the Rhinoceros software. This plugin is developed based on the methods of 3D Graphic Statics and Polyhedral Reciprocal Diagrams. The computational framework of this plugin uses new robust and efficient algorithms for the creation and modification of complex funicular, compression-only structural forms and is freely available
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A Novel Method for Assemblability Evaluation of Non-Ideal Cylindrical Parts Assembly Comput. Aided Des. (IF 3.156) Pub Date : 2021-01-19 Yue Li; Lihong Qiao; Zhicheng Huang; Nabil Anwer
The assemblability, which is the feasibility and difficulty of assembly, will greatly affect the efficiency and quality of assembly process, so assemblability analysis plays an important role during the design stage of products. Cylindrical parts assembly is a common structure with wide applications, whose assemblability can be affected by surface deviations, especially in some precision assemblies
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Discrete Gaussian Curvature Flow for Piecewise Constant Gaussian Curvature Surface Comput. Aided Des. (IF 3.156) Pub Date : 2021-01-14 Kazuki Hayashi; Yoshiki Jikumaru; Makoto Ohsaki; Takashi Kagaya; Yohei Yokosuka
A method is presented for generating a discrete piecewise constant Gaussian curvature (CGC) surface. An energy functional is first formulated so that its stationary point is the linear Weingarten (LW) surface, which has a property such that the weighted sum of mean and Gaussian curvatures is constant. The CGC surface is obtained using the gradient derived from the first variation of a special type
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A Unified Geometry Parametrization Method for Turbomachinery Blades Comput. Aided Des. (IF 3.156) Pub Date : 2021-01-02 Roberto Agromayor; Nitish Anand; Jens-Dominik Müller; Matteo Pini; Lars O. Nord
Turbomachinery design is increasingly carried out by means of automated workflows based on high-fidelity physical models and optimization algorithms. The parametrization of the blade geometry is an essential aspect of such workflows because it defines the design space in which an optimal solution can be found. Currently, parametrization methods used for this purpose are often tailored to one particular
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Geometry Design Using Function Representation on a Sparse Hierarchical Data Structure Comput. Aided Des. (IF 3.156) Pub Date : 2020-12-30 Sandilya Kambampati; Carolina Jauregui; Ken Museth; H. Alicia Kim
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Integrative design and fabrication methodology for bio-inspired folding mechanisms for architectural applications Comput. Aided Des. (IF 3.156) Pub Date : 2020-12-29 Axel Körner; Larissa Born; Oliver Bucklin; Seiichi Suzuki; Lauren Vasey; Götz T. Gresser; Achim Menges; Jan Knippers
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Enhanced Invariance Class Partitioning using Discrete Curvatures and Conformal Geometry Comput. Aided Des. (IF 3.156) Pub Date : 2020-12-30 Yifan Qie; Lihong Qiao; Nabil Anwer
Mesh models have been widely employed in current CAD/CAM systems, where the workpiece is considered as made up of a number of features limited by natural boundaries. The natural boundaries among features are in most cases edges where an abrupt change of point differential geometry properties occurs. However, such features and underlying surface portions could also be connected smoothly without an abrupt
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Multi-Axis Support-Free Printing of Freeform Parts with Lattice Infill Structures Comput. Aided Des. (IF 3.156) Pub Date : 2020-12-29 Yamin Li; Kai Tang; Dong He; Xiangyu Wang
In additive manufacturing, infill structures are commonly used to reduce the weight and cost of a solid part. Currently, most infill structure generation methods are based on the conventional 2.5-axis printing configuration, which, although able to satisfy the self-supporting condition on the infills, suffer from the well-known stair-case effect on the finished surface and the need of extensive support
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A Hardware-adaptive Deep Feature Matching Pipeline for Real-time 3D Reconstruction Comput. Aided Des. (IF 3.156) Pub Date : 2020-12-18 Shuai Zheng; Yabin Wang; Baotong Li; Xin Li
This paper presents a hardware-adaptive feature modeling framework to automatically generate and optimize deep neural networks to support real-time feature extraction and matching on a given hardware platform. This framework consists of a deep feature extraction and matching pipeline and a neural architecture search scheme, with which deep neural networks can be automatically generated and optimized
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Two-Stage Sector Partition Path Planning Method for Automated Fiber Placement on Complex Surfaces Comput. Aided Des. (IF 3.156) Pub Date : 2020-12-11 Jiaxin Gao; Weiwei Qu; Di Yang; Weidong Zhu; Yinglin Ke
Automated fiber placement (AFP) is an advanced composite manufacturing technology which is widely used in the production of complex shaped aircraft components. However, on the surface with large curvature, the fiber compaction performance is poor, and the direction deviation and the geodesic curvature of the path increase sharply with the offset distance, resulting in various placement defects. To
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A General Class of C1 Smooth Rational Splines: Application to Construction of Exact Ellipses and Ellipsoids Comput. Aided Des. (IF 3.156) Pub Date : 2020-12-08 Hendrik Speleers; Deepesh Toshniwal
In this paper, we describe a general class of C1 smooth rational splines that enables, in particular, exact descriptions of ellipses and ellipsoids — some of the most important primitives for CAD and CAE. The univariate rational splines are assembled by transforming multiple sets of NURBS basis functions via so-called design-through-analysis compatible extraction matrices; different sets of NURBS are
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The Construction of Conforming-to-shape Truss Lattice Structures via 3D Sphere Packing Comput. Aided Des. (IF 3.156) Pub Date : 2020-11-11 Boris van Sosin; Daniil Rodin; Hanna Sliusarenko; Michael Bartoň; Gershon Elber
Truss lattices are common in a wide variety of engineering applications, due to their high ratio of strength versus relative density. They are used both as the interior support for other structures, and as structures on their own. Using 3D sphere packing, we propose a set of methods for generating truss lattices that fill the interior of B-rep models, polygonal or (trimmed) NURBS based, of arbitrary
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A Fragment Fracture Surface Segmentation Method Based on Learning of Local Geometric Features on Margins Used for Automatic Utensil Reassembly Comput. Aided Des. (IF 3.156) Pub Date : 2020-11-18 Bin Liu; Mingzhe Wang; Xiaolei Niu; Shengfa Wang; Song Zhang; Jianxin Zhang
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Manufacturing of Screw Rotors Via 5-axis Double-Flank CNC Machining Comput. Aided Des. (IF 3.156) Pub Date : 2020-11-06 Michal Bizzarri; Michael Bartoň
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Improved Embedding of QR Codes onto Surfaces to be 3D Printed Comput. Aided Des. (IF 3.156) Pub Date : 2020-10-27 György Papp; Miklós Hoffmann; Ildikó Papp
Providing additional information for parts or items usually means to enclose it next to the object or affix it on the component when that is possible. However, another solution is available by gaining the benefits of an additive manufacturing technology, 3D printing. This technology makes it possible to embed the additional information onto the surface of the items, for example, in the forms of QR
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Valley Average of Lines (VAL) and of Directions (VAD) in 3D Comput. Aided Des. (IF 3.156) Pub Date : 2020-10-08 Mukul Sati; Jarek Rossignac
Extending (Sati et al., 2016) to 3D, we propose definitions and closed-form expressions for what we call the Valley Average of Directions (VAD), T→, of a set {T→i} of directions (unit vectors) and for what we call the Valley Average of Lines (VAL), L, of a set {Li} of lines. L is independent of the input order. When the {Li} are parallel, L is parallel to them and passes through the centroid of their
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Geometric Stability Classification: Datasets, Metamodels, and Adversarial Attacks Comput. Aided Des. (IF 3.156) Pub Date : 2020-10-15 Emma Lejeune
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Extracting Cycle-aware Feature Curve Networks from 3D Models Comput. Aided Des. (IF 3.156) Pub Date : 2020-10-06 Zhengda Lu; Jianwei Guo; Jun Xiao; Ying Wang; Xiaopeng Zhang; Dong-Ming Yan
Meaningful feature curves provide high-level shape representation of the geometrical shapes and are useful in various applications. In this paper, we propose an automatic method on the basis of the quadric surface fitting technique to extract complete feature curve networks (FCNs) from 3D surface meshes, as well as finding cycles and generating a high-quality segmentation. In the initial collection
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An Automated Approach for Execution Sequence-Driven Software and Physical Co-Design of Mechatronic Systems Based on Hybrid Functional Ontology Comput. Aided Des. (IF 3.156) Pub Date : 2020-09-23 Yue Cao; Yusheng Liu; Xiaoping Ye; Jianjun Zhao
Most mechatronic systems have becoming software-intensive. Even in their early design, the software and physical domains intersect with each other deeply. It is significant to capture and process the cross-domain influences automatically to avoid design defects in late stages. Semantic web technologies have been recognized as effective enabling technologies to support cross-domain knowledge representation
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On the Vertex-oriented Triangle Propagation (VTP) Algorithm: Parallelization and Approximation Comput. Aided Des. (IF 3.156) Pub Date : 2020-09-22 Jie Du; Ying He; Zheng Fang; Wenlong Meng; Shi-Qing Xin
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Aircraft Seam Feature Extraction from 3D Raw Point Cloud via Hierarchical Multi-structure Fitting Comput. Aided Des. (IF 3.156) Pub Date : 2020-09-22 Jiajia Dai; Mingqiang Wei; Qian Xie; Jun Wang
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Singularity Structure Simplification of Hexahedral Meshes via Weighted Ranking Comput. Aided Des. (IF 3.156) Pub Date : 2020-09-24 Gang Xu; Ran Ling; Yongjie Jessica Zhang; Zhoufang Xiao; Zhongping Ji; Timon Rabczuk
In this paper, we propose an improved singularity structure simplification method for hexahedral (hex) meshes using a weighted ranking approach. In previous work, the selection of to-be-collapsed base complex sheets/chords is only based on their thickness, which will introduce a few closed-loops and cause an early termination of simplification and a slow convergence rate. In this paper, a new weighted
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Image-Based Multiresolution Topology Optimization Using Deep Disjunctive Normal Shape Model Comput. Aided Des. (IF 3.156) Pub Date : 2020-09-28 Vahid Keshavarzzadeh; Mitra Alirezaei; Tolga Tasdizen; Robert M. Kirby
We present a machine learning framework for predicting the optimized structural topology designs using multiresolution data. Our approach primarily uses optimized designs from inexpensive coarse mesh finite element simulations for model training and generates high resolution images associated with simulation parameters that are not previously used. Our cost-efficient approach enables the designers
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Spectral Mesh-Free Quadrature for Planar Regions Bounded by Rational Parametric Curves Comput. Aided Des. (IF 3.156) Pub Date : 2020-09-16 David Gunderman; Kenneth Weiss; John A. Evans
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Object Synthesis by Learning Part Geometry with Surface and Volumetric Representations Comput. Aided Des. (IF 3.156) Pub Date : 2020-08-26 Sangpil Kim; Hyung-gun Chi; Karthik Ramani
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Least Degree G 1-refinable Multi-sided Surfaces Suitable for Inclusion into C 1 bi-2 Splines. Comput. Aided Des. (IF 3.156) Pub Date : 2020-08-22 Kȩstutis Karčiauskas,Jörg Peters
Geometrically smooth spline surfaces, generalized to include n-sided facets or configurations of n≠4 quads, can exhibit a curious lack of additional degrees of freedom for modeling or engineering analysis when refined. This paper establishes a minimal polynomial degree for smooth constructions of multi-sided surfaces that guarantees more flexibility in all directions under refinement. Degree bi-4 is
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Interacting with Self-Similarity Comput. Aided Des. (IF 3.156) Pub Date : 2020-08-21 Josef Graus; Alec Jacobson; Yotam Gingold
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ReliefNet: Fast Bas-relief Generation from 3D Scenes Comput. Aided Des. (IF 3.156) Pub Date : 2020-08-21 Zhongping Ji; Wei Feng; Xianfang Sun; Feiwei Qin; Yigang Wang; Yu-Wei Zhang; Weiyin Ma
Most previous methods of bas-relief generation run slow, or require tuning several important parameters. These issues seriously reduce the efficiency of bas-relief modeling. We introduce a fast generation method for high-quality bas-reliefs from 3D objects based on a deep learning technique. Unlike neural networks for image tasks, the proposed network for reliefs (ReliefNet) is elaborately designed
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Efficient contouring of functionally represented objects for additive manufacturing Comput. Aided Des. (IF 3.156) Pub Date : 2020-08-10 Dmitry Popov; Evgenii Maltsev; Oleg Fryazinov; Alexander Pasko; Iskander Akhatov
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Modeling the Internal Architecture of Composites Comput. Aided Des. (IF 3.156) Pub Date : 2020-08-19 F. Conde-Rodríguez; Á.L. García-Fernández; J.C. Torres
This paper introduces a flexible and easy to use method for designing complex composite heterogeneous materials. These materials feature two distinct phases called core and matrix that remain separate and distinct. Moreover, composite materials have an internal microarchitecture that have to be precisely modeled. All the microarchitecture examples that are shown in this paper have been modeled in the
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Universal material template for heterogeneous objects with applications to additive manufacturing Comput. Aided Des. (IF 3.156) Pub Date : 2020-08-19 Yunlong Tang; Yi Xiong; Sang-in Park; David W. Rosen
Additive manufacturing processes enable the fabrication of the material with multiscale complexities. However, to efficiently model the material compositions and microstructures on multiple design scales is an issue for most existing heterogeneous object modeling methods. To solve this problem, a universal material template and its associated heterogeneous object model are developed in this paper.
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Adaptive Concurrent Topology Optimization of Coated Structures with Nonperiodic Infill for Additive Manufacturing Comput. Aided Des. (IF 3.156) Pub Date : 2020-08-07 Van-Nam Hoang; Phuong Tran; Ngoc-Linh Nguyen; Klaus Hackl; H. Nguyen-Xuan
The present research develops a direct multiscale topology optimization method for additive manufacturing (AM) of coated structures with nonperiodic infill by employing an adaptive mapping technique of adaptive geometric components (AGCs). The AGCs consist of a framework of macro-sandwich bars that represent the macrostructure with the solid coating and a network of micro-solid bars that represent
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Quasi-Optimal Tool Trajectories for High Speed 2.5D Process Based on Morphological Transformation Comput. Aided Des. (IF 3.156) Pub Date : 2020-08-04 Ke Xu; Yingguang Li; Mengyuan Yang
2.5D processes are ubiquitous in pocket machining of structural parts as well as layer based additive manufacturing. Modern manufacturing systems are mostly integrated with high-speed motion capacity, which conventionally generated tool path cannot fully exploit due to large path stepover variation and sharp turnings at degenerated corners. Advanced geometric approaches strived to increase the local
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Lightweight Mesh File Format Using Repetition Pattern Encoding for Additive Manufacturing Comput. Aided Des. (IF 3.156) Pub Date : 2020-07-29 Benjamin Vaissier; Jean-Philippe Pernot; Laurent Chougrani; Philippe Véron
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Four-Dimensional Anisotropic Mesh Adaptation Comput. Aided Des. (IF 3.156) Pub Date : 2020-07-22 Philip Claude Caplan; Robert Haimes; David L. Darmofal; Marshall C. Galbraith
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Normal Estimation for 3D Point Clouds via Local Plane Constraint and Multi-scale Selection Comput. Aided Des. (IF 3.156) Pub Date : 2020-07-22 Jun Zhou; Hua Huang; Bin Liu; Xiuping Liu
In this paper, we propose a normal estimation method for unstructured 3D point clouds. In this method, a feature constraint mechanism called Local Plane Features Constraint (LPFC) is used and then a multi-scale selection strategy is introduced. The LPFC can be used in a single-scale point network architecture for a more stable normal estimation of the unstructured 3D point clouds. In particular, it
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Data-Driven Human Modeling by Sparse Representation Comput. Aided Des. (IF 3.156) Pub Date : 2020-07-15 Yiu-Bun Wu; Bin Liu; Xiuping Liu; Charlie C.L. Wang
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BeCOTS: Bent Corner-Operated Tran-Similar Maps and Lattices Comput. Aided Des. (IF 3.156) Pub Date : 2020-07-02 Kelsey Kurzeja; Jarek Rossignac
A field (2-parameter family of similarities) S(x,y) is Tran-Similar (TS) if there exist similarities U and V such that S(x,y)=Ux⋅Vy and U⋅V=V⋅U. The recently proposed COTS map, M, is defined in terms of a planar TS field, S, as M(x,y)=S(x,y)⋅A and is Corner-Operated (CO), i.e., controlled by the images A, B, C, and D of the four corners of the unit-square in parameter space. The CO property enables
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CHoCC: Convex Hull of Cospherical Circles and Applications to Lattices Comput. Aided Des. (IF 3.156) Pub Date : 2020-06-23 Yaohong Wu; Ashish Gupta; Kelsey Kurzeja; Jarek Rossignac
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Free-Floating Support Structure Generation Comput. Aided Des. (IF 3.156) Pub Date : 2020-06-25 Seongje Jang; Byungjin Moon; Kunwoo Lee
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Fast Automatic Knot Placement Method for Accurate B-spline Curve Fitting Comput. Aided Des. (IF 3.156) Pub Date : 2020-06-29 Raine Yeh; Youssef S.G. Nashed; Tom Peterka; Xavier Tricoche
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A Framework for Adaptive Width Control of Dense Contour-Parallel Toolpaths in Fused Deposition Modeling Comput. Aided Des. (IF 3.156) Pub Date : 2020-06-24 Tim Kuipers; Eugeni L. Doubrovski; Jun Wu; Charlie C.L. Wang
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Reconstruction of 3D Microstructures from 2D Images via Transfer Learning Comput. Aided Des. (IF 3.156) Pub Date : 2020-06-24 Ramin Bostanabad
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An Efficient Pattern Design Method for Plush Toys Using Component-Based Templates Comput. Aided Des. (IF 3.156) Pub Date : 2020-06-27 Yinghan Jin; Wanting Feng; Long Zeng; Dongliang Zhang
In pattern design of a 3D plush toy model, the key task is to draw seam lines on the 3D surface to divide it into surface patches to obtain 2D patterns. However, how to draw seam lines requires a lot of professional knowledge and skills of pattern design. In this paper, we present a new method that can guide and assist users to create 2D patterns of a 3D toy model efficiently. Based on a component-based
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Descriptive: Interactive 3D Shape Modeling from A Single Descriptive Sketch Comput. Aided Des. (IF 3.156) Pub Date : 2020-06-24 Cédric Bobenrieth; Frédéric Cordier; Arash Habibi; Hyewon Seo
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Automatic block decomposition based on dual surfaces Comput. Aided Des. (IF 3.156) Pub Date : 2020-06-02 Zhihao Zheng; Rui Wang; Shuming Gao; Yizhou Liao; Mao Ding
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NSGA-II approach for proper choice of nodes and knots in B-spline curve interpolation Comput. Aided Des. (IF 3.156) Pub Date : 2020-05-30 Liangchen Hu; Wensheng Zhang
Describing data, obtained by various instruments, with an analytic function is one of the tasks that people often face in a wide variety of applications such as virtual reality, CAD design, reverse engineering, data visualization, medical imaging, and cultural relic restoration and so on. Moreover, non-uniform B-spline is an extensively-used tool for interpolation which is an effective means of describing
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Concurrent density distribution and build orientation optimization of additively manufactured functionally graded lattice structures Comput. Aided Des. (IF 3.156) Pub Date : 2020-05-29 Cong Hong Phong Nguyen; Young Choi
Functionally graded conformal lattice structures (FGCLSs) are a particular type of lattice structure in which lattice unit cells are populated following structural boundaries and the density of the lattice unit cells is optimally distributed. Additionally, additively manufactured parts are reported to have anisotropic mechanical properties that highly depend on the part build orientations. This is
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Computing Smooth Quasi-geodesic Distance Field (QGDF) with Quadratic Programming Comput. Aided Des. (IF 3.156) Pub Date : 2020-05-21 Luming Cao; Junhao Zhao; Jian Xu; Shuangmin Chen; Guozhu Liu; Shiqing Xin; Yuanfeng Zhou; Ying He
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Fabricated shape estimation for additive manufacturing processes with uncertainty Comput. Aided Des. (IF 3.156) Pub Date : 2020-05-21 Svyatoslav Korneev; Ziyan Wang; Vaidyanathan Thiagarajan; Saigopal Nelaturi
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A Global G2 Spline Space with Improved Geometry Consistency Near Extraordinary Vertices Comput. Aided Des. (IF 3.156) Pub Date : 2020-05-18 Yue Ma; Weiyin Ma
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Sliding Basis Optimization for Heterogeneous Material Design Comput. Aided Des. (IF 3.156) Pub Date : 2020-05-16 Nurcan Gecer Ulu; Svyatoslav Korneev; Erva Ulu; Saigopal Nelaturi
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A feature-preserving framework for point cloud denoising Comput. Aided Des. (IF 3.156) Pub Date : 2020-05-11 Zheng Liu; Xiaowen Xiao; Saishang Zhong; Weina Wang; Yanlei Li; Ling Zhang; Zhong Xie
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