scholarly journals Problems of Creation and Usage of 3D Model of Structures and Theirs Possible Solution

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 181 ◽  
Author(s):  
Dalibor Bartonek ◽  
Michal Buday
Keyword(s):  
Computer Aided Design ◽  
3D Model ◽  
Three Dimensional ◽  
3D Models ◽  
Cad System ◽  
Building Models ◽  
Special Cad ◽  
Aided Design ◽  
The Church

This article describes problems that occur when creating three-dimensional (3D) building models. The first problem is geometric accuracy; the next is the quality of visualization of the resulting model. The main cause of this situation is that current Computer-Aided Design (CAD) software does not have sufficient means to precision mapping the measured data of a given object in field. Therefore the process of 3D model creation is mainly a relatively high proportion of manual work when connecting individual points, approximating curves and surfaces, or laying textures on surfaces. In some cases, it is necessary to generalize the model in the CAD system, which degrades the accuracy and quality of field data. The article analyzes these problems and then recommends several variants for their solution. There are described two basic methods: using topological codes in the list of coordinates points and creating new special CAD features while using Python scripts. These problems are demonstrated on examples of 3D models in practice. These are mainly historical buildings in different locations and different designs (brick or wooden structures). These are four sacral buildings in the Czech Republic (CR): the church of saints Johns of Brno-Bystrc, the Church of St. Paraskiva in Blansko, further the Strejc’s Church in Židlochovice, and Church of St. Peter in Alcantara in Karviná city. All of the buildings were geodetically surveyed by terrestrial method while using total station. The 3D model was created in both cases in the program AUTOCAD v. 18 and MicroStation.

scholarly journals AUTOMATION OF STRUCTURAL AND PARAMETRIC ANALYSIS OF PROJECT DECISIONS AND TRAINING OF THE DESIGNER OF MACHINE-BUILDING PRODUCTS WITH CAD COMPASS

2019 ◽  
Vol 2018 (2) ◽  
pp. 26-33
Author(s):  
Александр Афанасьев ◽  
Afanasyev Afanasyev ◽  
Сергей Бригаднов ◽  
Sergey Brigadnov
Keyword(s):  
Adaptive Learning ◽  
Computer Aided Design ◽  
Parametric Analysis ◽  
Three Dimensional ◽  
Machine Building ◽  
Building Products ◽  
Computer Aided ◽  
Design Solutions ◽  
Aided Design

The actual task in the field of computer-aided design of machine-building objects is to increase the level of automation of structural-parametric analysis of design solutions due to the repetition of their use, reducing the number of design operations and ensuring the corresponding competencies of designers. Developed methods and algorithms should ensure the acquisition of the necessary competencies for the designer for successful project activities in the field of computer-aided design, increasing the effectiveness of training. The system of analysis of design solutions should improve the quality of design solutions implemented in CAD KOMPAS-3D. In this paper, an overview of methods, systems and tools for analyzing design solutions implemented in the CAD-3D environment. The main features of such systems are described, their main disadvantages are identified: the lack of functions for determining non-optimal sequences of design operations, the inability to automatically rebuild a three-dimensional model of a machine-building product on the basis of analysis of the design model tree. A complex system for the analysis of project solutions and the training of a designer was developed and implemented, based on methods, models and algorithms for analysis and adaptive learning. The results of a computational experiment are presented, on the basis of which it can be concluded that the use of developed software enhances the efficiency and quality of the designer's training in the processes of constructing three-dimensional solid-state machine-building products in CAD KOMPAS-3D.

scholarly journals 3D Compression: from A to Zip a first complete example

2008 ◽  
Vol 15 (1) ◽  
pp. 9-38
Author(s):  
Thomas Lewiner
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
3D Models ◽  
Data Representation ◽  
Specific Class ◽  
Physical Simulations ◽  
Image Creation ◽  
Multidimensional Objects ◽  
Aided Design ◽  
Fast Access

Images invaded most of contemporary publications and communications. This expansion has accelerated with the development of efficient schemes dedicated to image compression. Nowadays, the image creation process relies on multidimensional objects generated from computer aided design, physical simulations, data representation or optimisation problem solutions. This variety of sources motivates the design of compression schemes adapted to specific class of models. The recent launch of Google Sketch’up and its 3D models warehouse has accelerated the shift from two-dimensional images to three-dimensional ones. However, these kind of systems require fast access to eventually huge models, which is possible only through the use of efficient compression schemes. This work is part of a tutorial given at the XXth Brazilian Symposium on Computer Graphics and Image Processing (Sibgrapi 2007).

scholarly journals DIGITAL SATELLITE MODEM RECEIVER DESIGNED WITH RUSSIAN-MADE ELECTRONIC COMPONENTS

2020 ◽  
Vol 258 (3) ◽  
pp. 60-64
Author(s):  
E.V. Belov ◽  
E.A. Brusin
Keyword(s):  
Computer Aided Design ◽  
3D Model ◽  
Electronic Components ◽  
Cad System ◽  
Computer Aided ◽  
Aided Design ◽  
Domestic Companies

In this paper we propose the design of the receiving path of an advanced satellite modem. The receiver comprises only the components produced by Russian domestic companies. The parameters of the receiver are discussed in the paper. 3D model of the receiver board obtained using the Altium Designer integrated computer-aided design (CAD) system is also presented.

Simulation-Based Ship Production Using Three-Dimensional CAD

2006 ◽  
Vol 22 (03) ◽  
pp. 155-159
Author(s):  
Yasuhisa Okumoto ◽  
Kentaro Hiyoku ◽  
Noritaka Uesugi
Keyword(s):  
Computer Aided Design ◽  
Complex Shape ◽  
Three Dimensional ◽  
Computer Integrated Manufacturing ◽  
Digital Manufacturing ◽  
Two Dimensional ◽  
Ship Structure ◽  
Cad System ◽  
Simulation Based ◽  
Aided Design

The application of three-dimensional computer-aided design (CAD) is becoming more popular for design and production in many industrial fields, and digital manufacturing is spreading. With preconstruction simulation of the production process using a three-dimensional digital model, which is a core of a computer-integrated manufacturing (CIM) system, the efficiency and safety of production can be improved at each stage of work and optimization of manufacturing can be achieved. This paper first describes the concept of simulation-based production in shipbuilding and digital manufacturing. The three-dimensional CAD system is indispensable for effective simulation because the ship structure is three-dimensionally complex, and threedimensional viewer software enables workers to examine structures on a computer display. With simulation, computer-optimized manufacturing is possible. Simulation is most effective for jobs in which many parties must cooperate to handle structures or equipment of complex shape. Two-dimensional drawings are inadequate for imaging whole figures in such cases. Some examples of the successful applications in IHI Marine United, Inc., are shown: erection of a complex hull block, scaffolding planning, and installation of a rudder.

Cataloging the 3D web: the availability of educational 3D models on the internet

2016 ◽  
Vol 34 (2) ◽  
pp. 239-258 ◽  
Author(s):  
Michael Groenendyk
Keyword(s):  
Computer Aided Design ◽  
3D Model ◽  
3D Models ◽  
3D Modelling ◽  
The Internet ◽  
Content Type ◽  
3D Printers ◽  
3D Printed ◽  
The Subject ◽  
Aided Design

Purpose – The number of 3D models available on the internet to both students and educators is rapidly expanding. Not only are the 3D model collections of popular websites like Thingiverse.com growing, organizations such as the Smithsonian Institution and NASA have also recently begun to build collections of 3D models and make these openly accessible online. Yet, even with increased interest in 3D printing and 3D scanning technologies, little is known about the overall structure of the 3D models available on the internet. The paper aims to discuss this issue. Design/methodology/approach – To initiate this project, a list was built of 33 of the most widely used 3D model websites on the internet. Freely downloadable models, as well as models available for purchase or as 3D printed objects were included in the list. Once the list of 33 websites was created, the data for each individual 3D model in the collections was manually assembled and recorded. The titles of the 3D models, keywords, subject headings, license information, and number of views and downloads were recorded, as this information was available. The data were gathered between January and May 2015, and compiled into a CSV database. To determine how online 3D model content relates to a variety of educational disciplines, relevant subject terms for a variety of educational disciples were extracted from the EBSCO database system. With this list of subject terms in hand, the keywords in the CSV database of model information were searched for each of the subject terms, with an automated process using a Perl script. Findings – There have been many teachers, professors, librarians and students who have purchased 3D printers with little or no 3D modelling skills. Without these skills the owners of these 3D printers are entirely reliant on the content created and freely shared by others to make use of their 3D printers. As the data collected for this research paper shows, the vast majority of open 3D model content available online pertains to the professions already well versed in 3D modelling and Computer Aided Design design, such as engineering and architecture. Originality/value – Despite that fact that librarians, teachers and other educators are increasingly using technologies that rely on open 3D model content as educational tools, no research has yet been done to assess the number of 3D models available online and what educational disciplines this content relates to. This paper attempts to fill this gap, providing an overview of the size of this content, the educational disciplines this content relates to and who has so far been responsible for developing this content. This information will be valuable to librarians and teachers currently working with technology such as 3D printers and virtual reality, as well as those considering investing in this technology.

scholarly journals Data Transfer Between CAD System and RP System: A Report

2012 ◽  
Author(s):  
Syaimak Abd. Syukur ◽  
Masine Md Tap
Keyword(s):  
Rapid Prototyping ◽  
Computer Aided Design ◽  
3D Model ◽  
Data Transfer ◽  
Cad System ◽  
System A ◽  
Computer Aided ◽  
Cad Cam ◽  
Cad Models ◽  
Aided Design

Sistem Rapid Prototyping (RP) ialah teknologi yang menukar sesuatu reka bentuk yang dibina dalam Computer Aided Design (CAD) ke suatu komponen model 3D. Model CAD biasanya dibina dalam sistem CAD yang kemudiannya dihantar ke sistem RP. Antaramuka yang baik antara sistem CAD dan sistem RP adalah salah satu faktor penting dalam menghasilkan prototaip yang berkualiti tinggi. Kertas kerja ini melaporkan hasil uji kaji yang dijalankan untuk mengenal pasti masalah-masalah dalam memindahkan data antara satu sistem CAD (UNIGRAPHICS) dan satu sistem RP (QUICKSLICE). Berdasarkan hasil uji kaji dan analisis yang dijalankan, satu garis panduan dicadangkan untuk perpindahan data yang lebih berkesan antara sistem CAD (UNIGRAPHICS) dan sistem RP (QUICKSLICE). Kata kunci: CAD; CAM; CAD/CAM; Rapid Prototyping Rapid Prototyping (RP) is a technology that transform a design generated in Computer Aided Design (CAD) to a 3D model parts. CAD models are usually done on a CAD system and then transported into the RP system. A good interface between the CAD and the RP system is one of the key factors of producing a good quality prototype. This paper reports on the results of an experimentation carried out to identify the problems in transferring data between a CAD system (UNIGRAPHICS) and an RP system (QUICKSLICE). Based on the experimentation’s results and analysis, a basic guideline is proposed for a safer data transfer between the CAD system (UNIGRAPHICS) and an RP system (QUICKSLICE). Key words: CAD; CAM; CAD/CAM; Rapid Prototyping

scholarly journals Homomorphic Encryption-Based Robust Reversible Watermarking for 3D Model

Symmetry ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 347 ◽  
Author(s):  
Li Li ◽  
Shengxian Wang ◽  
Shanqing Zhang ◽  
Ting Luo ◽  
Ching-Chun Chang
Keyword(s):  
3D Model ◽  
Homomorphic Encryption ◽  
Three Dimensional ◽  
3D Models ◽  
Reversible Watermarking ◽  
Histogram Shifting ◽  
Watermark Embedding ◽  
Paillier Cryptosystem ◽  
Embed Watermark

Robust reversible watermarking in an encrypted domain is a technique that preserves privacy and protects copyright for multimedia transmission in the cloud. In general, most models of buildings and medical organs are constructed by three-dimensional (3D) models. A 3D model shared through the internet can be easily modified by an unauthorized user, and in order to protect the security of 3D models, a robust reversible 3D models watermarking method based on homomorphic encryption is necessary. In the proposed method, a 3D model is divided into non-overlapping patches, and the vertex in each patch is encrypted by using the Paillier cryptosystem. On the cloud side, in order to utilize addition and multiplication homomorphism of the Paillier cryptosystem, three direction values of each patch are computed for constructing the corresponding histogram, which is shifted to embed watermark. For obtaining watermarking robustness, the robust interval is designed in the process of histogram shifting. The watermark can be extracted from the symmetrical direction histogram, and the original encrypted model can be restored by histogram shifting. Moreover, the process of watermark embedding and extraction are symmetric. Experimental results show that compared with the existing watermarking methods in encrypted 3D models, the quality of the decrypted model is improved. Moreover, the proposed method is robust to common attacks, such as translation, scaling, and Gaussian noise.

scholarly journals Deep Common Semantic Space Embedding for Sketch-Based 3D Model Retrieval

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 369 ◽  
Author(s):  
Jing Bai ◽  
Mengjie Wang ◽  
Dexin Kong
Keyword(s):  
Visual Perception ◽  
Computer Aided Design ◽  
3D Model ◽  
Semantic Content ◽  
3D Models ◽  
Semantic Space ◽  
3D Model Retrieval ◽  
Novel Approach ◽  
Model Retrieval ◽  
Aided Design

Sketch-based 3D model retrieval has become an important research topic in many applications, such as computer graphics and computer-aided design. Although sketches and 3D models have huge interdomain visual perception discrepancies, and sketches of the same object have remarkable intradomain visual perception diversity, the 3D models and sketches of the same class share common semantic content. Motivated by these findings, we propose a novel approach for sketch-based 3D model retrieval by constructing a deep common semantic space embedding using triplet network. First, a common data space is constructed by representing every 3D model as a group of views. Second, a common modality space is generated by translating views to sketches according to cross entropy evaluation. Third, a common semantic space embedding for two domains is learned based on a triplet network. Finally, based on the learned features of sketches and 3D models, four kinds of distance metrics between sketches and 3D models are designed, and sketch-based 3D model retrieval results are achieved. The experimental results using the Shape Retrieval Contest (SHREC) 2013 and SHREC 2014 datasets reveal the superiority of our proposed method over state-of-the-art methods.

A Computer-Aided-Design (CAD) System for Four-Step Three-Dimensional Braiding

2015 ◽  
Vol 1120-1121 ◽  
pp. 1429-1434
Author(s):  
Qi Wang ◽  
Jian Ming Wang
Keyword(s):  
Mechanical Properties ◽  
Computer Aided Design ◽  
Geometric Modeling ◽  
Three Dimensional ◽  
Structure Design ◽  
Braided Composite ◽  
Cad System ◽  
Cad Simulation ◽  
Aided Design ◽  
Geometric Study

To estimate the precise mechanical properties of the three-dimensional (3D) braided composite, a geometric study is needed. Owing to the complexity of the yarn paths inside the preform, the geometric modeling for 3D braided composite is always time consuming. In this paper, an efficient method, namely preform boundary reflection (PBR) method, is proposed for motion model construction in geometric study. Furthermore, the CAD simulation system was developed for integral geometric descriptions of 3D braided preform with different parameters. Compared with the traditional method, the novel method significantly simplifies the simulation process without affecting the precision of geometric structure. As a result, the structure design for composite preform is effectively accelerated. The new method establishes the foundation of microstructure and mechanical properties analysis for the preforms with complex geometric structures.

scholarly journals Real time object customization in CAD system

2019 ◽  
Vol 15 (2) ◽  
pp. 1066
Author(s):  
Z. F. Z. Abidin ◽  
M. N. Osman Zahid
Keyword(s):  
Real Time ◽  
Computer Aided Design ◽  
3D Model ◽  
Visual Basic ◽  
Cad System ◽  
Model Modification ◽  
Software Interface ◽  
Cad Cam ◽  
Aided Design ◽  
Cam Software

Object customization in Computer Aided Design (CAD) is a method used to modify the sketch parameters and change the model geometries. This method is one of important features in part modelling which empowered CAD user to simply modify their product. The conventional method of modifying CAD model is usually relied on the manual editing. This paper outlines a development of program than can be integrated in CAD/CAM system for real time object customization. It uses Visual Basic (VB) programming with custom Graphical User Interface (GUI) generated in NX10 (CAD/CAM software) interface. The main contribution of this research is a tool for real time object customization that capable to assist the modification of 3D model. In order to develop the tool, 3D model modification instructions are translated into programming codes by using Journaling tools in NX interface. Editable parameters are identified based on the model shapes. The related codes are reconstructed, modified and linked to the functional GUI.  This allows user to simply modify the model shapes in real time with minimum process steps. The performance of the method is evaluated in terms of the reduction of process steps and time in modifying the 3D model in CAD system. All the findings and details of approach are presented.

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