scholarly journals Integration of Explicit Geometric Constraints in the Comparison of 3D CAD Models for Part Design Reuse

2012 ◽  
pp. 445-457
Author(s):  
Antoine Brière-Côté ◽  
Louis Rivest ◽  
Roland Maranzana
Keyword(s):  
Geometric Constraints ◽  
Design Reuse ◽  
3D Cad ◽  
Cad Models

scholarly journals Automatized Evaluation of Students’ CAD Models

2021 ◽  
Vol 11 (4) ◽  
pp. 145
Author(s):  
Nenad Bojcetic ◽  
Filip Valjak ◽  
Dragan Zezelj ◽  
Tomislav Martinec
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Computer Application ◽  
Test Cases ◽  
Cad Model ◽  
Computer Solution ◽  
3D Cad ◽  
Computer Aided ◽  
Cad Models ◽  
Aided Design

The article describes an attempt to address the automatized evaluation of student three-dimensional (3D) computer-aided design (CAD) models. The driving idea was conceptualized under the restraints of the COVID pandemic, driven by the problem of evaluating a large number of student 3D CAD models. The described computer solution can be implemented using any CAD computer application that supports customization. Test cases showed that the proposed solution was valid and could be used to evaluate many students’ 3D CAD models. The computer solution can also be used to help students to better understand how to create a 3D CAD model, thereby complying with the requirements of particular teachers.

Graph Representation of 3D CAD Models for Machining Feature Recognition With Deep Learning

2021 ◽  
Author(s):  
Weijuan Cao ◽  
Trevor Robinson ◽  
Hua Yang ◽  
Flavien Boussuge ◽  
Andrew Colligan ◽  
...  
Keyword(s):  
Deep Learning ◽  
Feature Recognition ◽  
Graph Representation ◽  
3D Cad ◽  
Machining Feature ◽  
Cad Models

A 3D CAD model input pipeline for REFMUL3 full-wave FDTD 3D simulator

2021 ◽  
Vol 16 (11) ◽  
pp. C11013
Author(s):  
J.M. Santos ◽  
E. Ricardo ◽  
F.J. da Silva ◽  
T. Ribeiro ◽  
S. Heuraux ◽  
...  
Keyword(s):  
Vessel Wall ◽  
Thermal Protection ◽  
Interface Problem ◽  
Cad Model ◽  
Fusion Plasma ◽  
3D Cad ◽  
Full Wave ◽  
Wall Structures ◽  
Design Cycle ◽  
Cad Models

Abstract The use of advanced simulation has become increasingly more important in the planning, design, and assessment phases of future fusion plasma diagnostics, and in the interpretation of experimental data from existing ones. The design cycle of complex reflectometry systems, such as the ones being planned for next generation machines (IDTT and DEMO), relies heavily on the results produced by synthetic diagnostics, used for system performance evaluation and prediction, both crucial in the design process decision making. These synthetic diagnostics need realistic representations of all system components to incorporate the main effects that shape their behavior. Some of the most important elements that are required to be well modelled and integrated in simulations are the wave launcher structures, such as the waveguides, tapers, and antennas, as well as the vessel wall structures and access to the plasma. The latter are of paramount importance and are often neglected in this type of studies. Faithfully modelling them is not an easy task, especially in 3D simulations. The procedure herein proposed consists in using CAD models of a given machine, together with parameterizable models of the launcher, to produce a description suited for Finite Difference Time Domain (FDTD) 3D simulation, combining the capabilities of real-world CAD design with the power of simulation. However, CAD model geometric descriptions are incompatible with the ones used by standard FDTD codes. CAD software usually outputs models in a tessellated mesh while FDTD simulators use Volumetric Pixel (VOXEL) descriptions. To solve this interface problem, we implemented a pipeline to automatically convert complex CAD models of tokamak vessel components and wave launcher structures to the VOXEL input required by REFMUL3, a full wave 3D Maxwell FDTD parallel code. To illustrate the full procedure, a complex reflectometry synthetic diagnostic for IDTT was setup, converted and simulated. This setup includes 3 antennas recessed into the vessel wall, for thermal protection, one for transmission and reception, and two just for reception.

User-Driven Computer-Assisted Reverse Engineering of Editable CAD Assembly Models

2021 ◽  
pp. 1-16
Author(s):  
Ghazanfar Ali Shah ◽  
Jean-Philippe Pernot ◽  
Arnaud Polette ◽  
Franca Giannini ◽  
Marina Monti
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Point Clouds ◽  
Geometric Constraints ◽  
Computer Assisted ◽  
Reconstruction Process ◽  
Mechanical Parts ◽  
Starting Point ◽  
Cad Models ◽  
Incomplete Datasets

Abstract This paper introduces a novel reverse engineering technique for the reconstruction of editable CAD models of mechanical parts' assemblies. The input is a point cloud of a mechanical parts' assembly that has been acquired as a whole, i.e. without disassembling it prior to its digitization. The proposed framework allows for the reconstruction of the parametric CAD assembly model through a multi-step reconstruction and fitting approach. It is modular and it supports various exploitation scenarios depending on the available data and starting point. It also handles incomplete datasets. The reconstruction process starts from roughly sketched and parameterized geometries (i.e 2D sketches, 3D parts or assemblies) that are then used as input of a simulated annealing-based fitting algorithm, which minimizes the deviation between the point cloud and the reconstructed geometries. The coherence of the CAD models is maintained by a CAD modeler that performs the updates and satisfies the geometric constraints as the fitting process goes on. The optimization process leverages a two-level filtering technique able to capture and manage the boundaries of the geometries inside the overall point cloud in order to allow for local fitting and interfaces detection. It is a user-driven approach where the user decides what are the most suitable steps and sequence to operate. It has been tested and validated on both real scanned point clouds and as-scanned virtually generated point clouds incorporating several artifacts that would appear with real acquisition devices.

Investigating the Use of Large-Scale Immersive Computing Environments in Collaborative Design

2014 ◽  
Author(s):  
Meisha Rosenberg ◽  
Judy M. Vance
Keyword(s):  
Design Process ◽  
Collaborative Design ◽  
Large Scale ◽  
Design Teams ◽  
Team Members ◽  
3D Cad ◽  
Cad Models ◽  
Computing Environments ◽  
Design Ideas ◽  
Human Motions

Successful collaborative design requires in-depth communication between experts from different disciplines. Many design decisions are made based on a shared mental model and understanding of key features and functions before the first prototype is built. Large-Scale Immersive Computing Environments (LSICEs) provide the opportunity for teams of experts to view and interact with 3D CAD models using natural human motions to explore potential design configurations. This paper presents the results of a class exercise where student design teams used an LSICE to examine their design ideas and make decisions during the design process. The goal of this research is to gain an understanding of (1) whether the decisions made by the students are improved by full-scale visualizations of their designs in LSICEs, (2) how the use of LSICEs affect the communication of students with collaborators and clients, and (3) how the interaction methods provided in LSICEs affect the design process. The results of this research indicate that the use of LSICEs improves communication among design team members.

Development and Implementation of Shape Comparison of 3D CAD Models

2009 ◽  
Author(s):  
Sagar Chowdhury ◽  
Zahed Siddique
Keyword(s):  
Computer Hardware ◽  
Efficient Design ◽  
User Friendliness ◽  
Specialized Knowledge ◽  
3D Cad ◽  
Large Databases ◽  
Modeling Software ◽  
Cad Models ◽  
Near Future ◽  
Selection Of

With the advancements of 3D modeling software, the use of CAD in design has become a standard practice. In recent years development in computer hardware and improvements in user friendliness of the CAD software has allowed designers to quickly and easily modify the CAD models. This modification capability allows CAD to be an integral part of the design process. Due to the increase in global competition, companies have become increasingly interested in fast and efficient design processes. One way to achieve improved efficiency is through better collaboration among designers working in common or similar projects and disciplines. A large design problem often requires specialized knowledge from several fields. Collaboration among the designers from these fields will ensure efficient design. Interaction among the designers can prevent redesign of similar components/subsystems, which requires the ability to share their designs. With the increase of collaboration, designers can now get access to large databases of 3D CAD models. But the challenge lies in search capabilities to identify common models from a large database. These considerations suggest that in the near future a challenge in 3D CAD industry will be how to find models of similar components and products. This paper presents an approach and its implementation to measure the similarity among a number of CAD models. The approach is based on the extraction and organization of information from the CAD models, which is followed by the suitable selection of commonality index and calculation of the commonality among a set of CAD models. A set of Vacuum cleaners are modeled and then compared to demonstrate the application of the approach.

Creating by Imagining: Use of Natural and Intuitive BCI in 3D CAD Modeling

2013 ◽  
Author(s):  
Sree Shankar S. ◽  
Anoop Verma ◽  
Rahul Rai
Keyword(s):  
3D Modeling ◽  
Signal Acquisition ◽  
Natural Interaction ◽  
Brain Wave ◽  
3D Cad ◽  
Facial Movements ◽  
Brain Signals ◽  
Computer Aided ◽  
Cad Models ◽  
Google Sketchup

Since its inception, computer aided 3D modeling has primarily relied on the Windows, Icons, Menus, Pointer (WIMP) user interface. WIMP has rarely been able to tap into the natural intuitiveness and imagination of the user which accompanies any design process. Brain-computer interface (BCI) is a novel modality that uses the brain signals of a user to enable natural and intuitive interaction with an external device. The BCI’s potential to become an important modality of natural interaction for 3D modeling is almost limitless and unexplored. In theory, using BCI one can create any 3D model by simply thinking about it. This paper presents a basic framework for using BCI as an interface for computer aided 3D modeling. This framework involves the task of recording and recognizing electroencephalogram (EEG) brain wave patterns and electromyogram (EMG) signals corresponding to facial movements. The recognized EEG/EMG brain signals and associated keystrokes are used to activate/control different commands of a CAD package. Eight sample CAD models are created using the Emotiv EEG head set based BCI interface and Google SketchUp and presented to demonstrate the efficacy of the developed system based on the framework. To further exhibit BCI’s usability, human factor studies have been carried out on subjects from different backgrounds. Based on preliminary results, it is concluded that EEG/EMG based BCI is suitable for computer aided 3D modeling purposes. Issues in signal acquisition, system flexibility, integration with other modalities, and data collection are also discussed.

Direct Building Manufacturing of Homes with Digital Fabrication

2012 ◽  
pp. 71-82 ◽  
Author(s):  
Lawrence Sass
Keyword(s):  
Digital Fabrication ◽  
Information Modeling ◽  
3D Cad ◽  
The Core ◽  
Construction Techniques ◽  
Building Information ◽  
Cad Cam ◽  
Cad Models ◽  
Paper Documentation ◽  
Small Building

Architecture, engineering, and construction industries maintain a long standing desire to enhance design communication through various forms of 3D CAD modeling. In spite the introduction of Building Information Modeling (BIM), designers and builders expect varying amounts of communication loss once construction has started due to indirect construction techniques or hand based methods to manufacture buildings. This is especially true for houses and small structures, buildings that makeup the core of villages and suburbs. Unfortunately, paper documentation and reading 3D CAD models on screen continue the trend of indirect production defined in most manufacturing industries as error. The emerging application of CAD/CAM within design and construction industries provides hope for elevated communication between design and building. With CAD/CAM, it is possible to manufacture buildings of all types and sizes directly from CAD files similar to mass produced artifacts, thus reducing complexity in communication between parties. This chapter is presentation of one process of direct manufacturing from CAD and the emerging possibilities for small building production using digital fabrication. The chapter will focus on houses to illustrate the potential of direct manufacturing of buildings from CAD data.

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