Tight Cocone: A Water-tight Surface Reconstructor

2003 ◽  
Vol 3 (4) ◽  
pp. 302-307 ◽  
Author(s):  
Tamal K. Dey ◽  
Samrat Goswami
Keyword(s):  
Surface Reconstruction ◽  
Computer Aided Design ◽  
Simple Algorithm ◽  
Reconstruction Algorithm ◽  
Data Sets ◽  
Triangulated Surface ◽  
Output Surface ◽  
Input Sample ◽  
Sample Points ◽  
Aided Design

Surface reconstruction from unorganized sample points is an important problem in computer graphics, computer aided design, medical imaging and solid modeling. Recently a few algorithms have been developed that have theoretical guarantee of computing a topologically correct and geometrically close surface under certain condition on sampling density. Unfortunately, this sampling condition is not always met in practice due to noise, non-smoothness or simply due to inadequate sampling. This leads to undesired holes and other artifacts in the output surface. Certain CAD applications such as creating a prototype from a model boundary require a water-tight surface, i.e., no hole should be allowed in the surface. In this paper we describe a simple algorithm called Tight Cocone that works on an initial mesh generated by a popular surface reconstruction algorithm and fills up all holes to output a water-tight surface. In doing so, it does not introduce any extra points and produces a triangulated surface interpolating the input sample points. In support of our method we present experimental results with a number of difficult data sets.

scholarly journals A SIMPLE ALGORITHM FOR HOMEOMORPHIC SURFACE RECONSTRUCTION

2002 ◽  
Vol 12 (01n02) ◽  
pp. 125-141 ◽  
Author(s):  
NINA AMENTA ◽  
SUNGHEE CHOI ◽  
TAMAL K. DEY ◽  
NAVEEN LEEKHA
Keyword(s):  
Computer Vision ◽  
Computer Graphics ◽  
Surface Reconstruction ◽  
Linear Approximation ◽  
Piecewise Linear ◽  
Simple Algorithm ◽  
Piecewise Linear Approximation ◽  
Original Surface ◽  
Output Surface ◽  
Sample Points

The problem of computing a piecewise linear approximation to a surface from a set of sample points is important in solid modeling, computer graphics and computer vision. A recent algorithm1 using the Voronoi diagram of the sample points gave a guarantee on the distance of the output surface from the original sampled surface assuming that the sample was sufficiently dense. We give a similar algorithm, simplifying the computation and the proof of the geometric guarantee. In addition, we guarantee that our output surface is homeomorphic to the original surface; to our knowledge this is the first such topological guarantee for this problem.

Boundary Surface Recovery From Skeleton Elements: Part I — Skeleton Curves

1992 ◽  
Author(s):  
Sean M. Gelston ◽  
Debasish Dutta
Keyword(s):  
Inverse Problem ◽  
Computer Aided Design ◽  
Boundary Surface ◽  
Reconstruction Algorithm ◽  
Companion Paper ◽  
Active Area ◽  
Curves And Surfaces ◽  
Computer Aided ◽  
Aided Design ◽  
Boundary Surfaces

Abstract Skeleton curves and surfaces have many applications in computer aided design and analysis. Construction of skeletons is an active area of research. We consider the inverse problem that of recovering boundary surfaces from given skeleton elements. The skeleton of any 3D object will, in general, consist of curves and surfaces. Therefore, any boundary reconstruction algorithm must systematically process the surfaces generated by the skeletal curves and the skeletal surfaces. In this paper (Part I) we present algorithms for reconstructing boundary surfaces corresponding to skeletal curves. Implemented examples are also included. In a companion paper (Part II) we consider skeletal elements that are surfaces.

scholarly journals Applicability of Formwork Automation Design Software for Aluminum Formwork

2020 ◽  
Vol 10 (24) ◽  
pp. 9029
Author(s):  
Bokyeong Lee ◽  
Hyeonggil Choi ◽  
Byongwang Min ◽  
Dong-Eun Lee
Keyword(s):  
Computer Aided Design ◽  
Building Information Modeling ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Information Modeling ◽  
Two Dimensional ◽  
Building Information ◽  
Design Software ◽  
Modeling Data ◽  
Aided Design

In this study, by applying the developed formwork automation design software to three target structures, we reviewed the applicability of the formwork automation design software for the aluminum formwork. To apply the formwork automation design software, we built an aluminum formwork library based on the conversion of two-dimensional (2D) computer-aided design (CAD) data to three-dimensional building information modeling data for all the components of the aluminum formwork. The results of the automated formwork layout on the target structures using the formwork automation design software confirmed that the wall and deck members were laid out by the set algorithm according to the formwork size and direction. However, because of the limited functionality of the software, the level of completion of the formwork layout was found to be lower than that of the manual formwork layout based on 2D CAD data. The currently developed software is based on a simple algorithm, but has a drawback in that the automated layout is limited to only some of its members. Therefore, additional research should be conducted on the development of advanced software through the diversification of the algorithm, automation of preprocessing of the mesh, and analysis of the relationships of all the members comprising the formwork.

scholarly journals Sensor Architectures and Technologies for Upper Limb 3D Surface Reconstruction: A Review

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6584
Author(s):  
Alessandro Paoli ◽  
Paolo Neri ◽  
Armando V. Razionale ◽  
Francesco Tamburrino ◽  
Sandro Barone
Keyword(s):  
Surface Reconstruction ◽  
Upper Limb ◽  
Computer Aided Design ◽  
Ongoing Research ◽  
Optical Scanning ◽  
Time Scanning ◽  
Starting Point ◽  
Depth Analysis ◽  
Processing Effort ◽  
Aided Design

3D digital models of the upper limb anatomy represent the starting point for the design process of bespoke devices, such as orthoses and prostheses, which can be modeled on the actual patient’s anatomy by using CAD (Computer Aided Design) tools. The ongoing research on optical scanning methodologies has allowed the development of technologies that allow the surface reconstruction of the upper limb anatomy through procedures characterized by minimum discomfort for the patient. However, the 3D optical scanning of upper limbs is a complex task that requires solving problematic aspects, such as the difficulty of keeping the hand in a stable position and the presence of artefacts due to involuntary movements. Scientific literature, indeed, investigated different approaches in this regard by either integrating commercial devices, to create customized sensor architectures, or by developing innovative 3D acquisition techniques. The present work is aimed at presenting an overview of the state of the art of optical technologies and sensor architectures for the surface acquisition of upper limb anatomies. The review analyzes the working principles at the basis of existing devices and proposes a categorization of the approaches based on handling, pre/post-processing effort, and potentialities in real-time scanning. An in-depth analysis of strengths and weaknesses of the approaches proposed by the research community is also provided to give valuable support in selecting the most appropriate solution for the specific application to be addressed.

Optimal Sensor Design Using Patient-Specific Images

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Sukhi Basati ◽  
Timothy J. Harris ◽  
Andreas A. Linninger
Keyword(s):  
Computer Aided Design ◽  
Rational Design ◽  
Treatment Options ◽  
Patient Specific ◽  
Data Sets ◽  
Disease States ◽  
Magnetic Resonance Data ◽  
Computer Aided ◽  
Aided Design ◽  
Pathological Disease

In diseases such as hydrocephalus, the cerebral ventricles enlarge. The treatment options for these patients are presently based on pressure, which has limited capabilities. We present the design of a volume sensor as an alternative monitoring option. Through the use of computer aided design and simulation, we optimized a sensor in silico with fewer resources. Specifically, we designed a sensor for animal experimentation with a scalable procedure for human sensors. In this paper, we present a rational design approach for a sensor that integrates advances in medical imaging. Magnetic resonance data sets of both normal and diseased subjects were used as a virtual laboratory. Finite element simulations were performed under pathological disease states of the brain as a contribution toward an accelerated device design. An optimized sensor was then fabricated for these subjects based on the outcome of the simulations. In this paper, we explain how a computer aided subject-specific design was used to help fabricate and test our sensor.

scholarly journals Beam Hardening Artifact Reduction in X-Ray CT Reconstruction of 3D Printed Metal Parts Leveraging Deep Learning and CAD Models

2020 ◽  
Author(s):  
Amirkoushyar Ziabari ◽  
Singanallur Venkatakrishnan ◽  
Michael Kirka ◽  
Paul Brackman ◽  
Ryan Dehoff ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Critical Role ◽  
Simulated Data ◽  
Data Sets ◽  
Ct Reconstruction ◽  
Reconstruction Algorithms ◽  
Beam Hardening ◽  
X Ray ◽  
Cad Models ◽  
Aided Design

Abstract Nondestructive evaluation (NDE) of additively manufactured (AM) parts is important for understanding the impacts of various process parameters and qualifying the built part. X-ray computed tomography (XCT) has played a critical role in rapid NDE and characterization of AM parts. However, XCT of metal AM parts can be challenging because of artifacts produced by standard reconstruction algorithms as a result of a confounding effect called “beam hardening.” Beam hardening artifacts complicate the analysis of XCT images and adversely impact the process of detecting defects, such as pores and cracks, which is key to ensuring the quality of the parts being printed. In this work, we propose a novel framework based on using available computer-aided design (CAD) models for parts to be manufactured, accurate XCT simulations, and a deep-neural network to produce high-quality XCT reconstructions from data that are affected by noise and beam hardening. Using extensive experiments with simulated data sets, we demonstrate that our method can significantly improve the reconstruction quality, thereby enabling better detection of defects compared with the state of the art. We also present promising preliminary results of applying the deep networks trained using CAD models to experimental data obtained from XCT of an AM jet-engine turbine blade.

Boundary Surface Recovery From Skeleton Elements: Part II — Skeleton Surfaces

1992 ◽  
Author(s):  
Sean M. Gelston ◽  
Debasish Dutta
Keyword(s):  
Inverse Problem ◽  
Computer Aided Design ◽  
Boundary Surface ◽  
Reconstruction Algorithm ◽  
Companion Paper ◽  
Active Area ◽  
Curves And Surfaces ◽  
Computer Aided ◽  
Aided Design ◽  
Boundary Surfaces

Abstract Skeleton curves and surfaces have many applications in computer aided design and analysis and the construction of skeletons has been an active area of research. We consider the inverse problem that of recovering boundary surfaces from given skeleton elements. The skeleton of any 3D object will, in general, consist of curves and surfaces. Therefore, any boundary reconstruction algorithm must systematically process the surfaces generated by the skeletal curves and the skeletal surfaces. In a companion paper (Part I) we considered the reconstruction of boundaries corresponding to skeletal curves. In this paper (Part II) we consider the reconstruction of boundaries corresponding to skeletal elements that are surfaces. Implemented examples are also included.

scholarly journals ANN Synthesis Model of Single-Feed Corner-Truncated Circularly Polarized Microstrip Antenna with an Air Gap for Wideband Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhongbao Wang ◽  
Shaojun Fang
Keyword(s):  
Computer Aided Design ◽  
Microstrip Antenna ◽  
Microstrip Antennas ◽  
Air Gap ◽  
Training Data ◽  
Data Sets ◽  
Circularly Polarized ◽  
Artificial Neural Network Ann ◽  
Aided Design ◽  
Lm Algorithm

A computer-aided design model based on the artificial neural network (ANN) is proposed to directly obtain patch physical dimensions of the single-feed corner-truncated circularly polarized microstrip antenna (CPMA) with an air gap for wideband applications. To take account of the effect of the air gap, an equivalent relative permittivity is introduced and adopted to calculate the resonant frequency andQ-factor of square microstrip antennas for obtaining the training data sets. ANN architectures using multilayered perceptrons (MLPs) and radial basis function networks (RBFNs) are compared. Also, six learning algorithms are used to train the MLPs for comparison. It is found that MLPs trained with the Levenberg-Marquardt (LM) algorithm are better than RBFNs for the synthesis of the CPMA. An accurate model is achieved by using an MLP with three hidden layers. The model is validated by the electromagnetic simulation and measurements. It is enormously useful to antenna engineers for facilitating the design of the single-feed CPMA with an air gap.

Consistency in Spatial Databases

2005 ◽  
pp. 93-98 ◽  
Author(s):  
M. Andrea Rodríguez-Tastets
Keyword(s):  
Spatial Data ◽  
Computer Aided Design ◽  
Large Scale ◽  
Spatial Databases ◽  
Data Sets ◽  
Navigation Systems ◽  
Large Scale Integration ◽  
Spatial Data Sets ◽  
Scale Integration ◽  
Aided Design

During the past several years, traditional databases have been enhanced to include spatially referenced data. Spatial database management (SDBM) systems aim at providing models for the efficient manipulation of data related to space. Such type of manipulation is useful for any type of applications based on large spatial data sets, such as computer-aided design (CAD), very large scale integration (VLSI), robotics, navigation systems, and image processing.

Adaptive Subdivision Surface Reconstruction for Scattered Data in Reverse Engineering Based on GPU

2012 ◽  
Vol 490-495 ◽  
pp. 138-142
Author(s):  
Ying Hui Wang ◽  
Wei Yong Wu
Keyword(s):  
Reverse Engineering ◽  
Surface Reconstruction ◽  
Large Scale ◽  
High Efficiency ◽  
Reconstruction Algorithm ◽  
Scattered Data ◽  
Data Sets ◽  
Reconstruction Method ◽  
Subdivision Surface ◽  
Adaptive Subdivision

Reconstructing geometry models from scattered data is an important task in reverse engineering. An adaptive subdivision surface reconstruction method was proposed to construct complex models rapidly. This method includes several steps: triangulation on scattered data; mesh segmentation and simplification; computing the subdivision depth according to the specified error. The last step is computing mesh control net by fitting subdivision functions and construct subdivision surface adaptively. In order to improve the efficiency of the algorithm, we implemented the reconstruction algorithm on GPU in parallel way and tested the program on several large scale data sets. Our adaptive subdivision method can save storage space and gain high efficiency simultaneously.

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