scholarly journals Triangulation of 3D Surfaces Recovered from STL Grids

10.14311/620 ◽  
2004 ◽  
Vol 44 (5-6) ◽  
Author(s):  
D. Rypl ◽  
Z. Bittnar
Keyword(s):  
Feature Recognition ◽  
Boundary Representation ◽  
Attractive Alternative ◽  
File Format ◽  
Stl File ◽  
Advancing Front ◽  
Discrete Surfaces ◽  
The Family ◽  
Reconstructed Surface ◽  
3D Surfaces

In the present paper, an algorithm for the discretization of parametric 3D surfaces has been extended to the family of discrete surfaces represented by stereolithography (STL) grids. The STL file format, developed for the rapid prototyping industry, is an attractive alternative to surface representation in solid modeling. Initially, a boundary representation is constructed from the STL file using feature recognition. Then a smooth surface is recovered over the original STL grid using an interpolating subdivision procedure. Finally, the reconstructed surface is subjected to the triangulation accomplished using the advancing front technique operating directly on the surface. The capability of the proposed methodology is illustrated on an example. 

Research on the Three-Dimensional Displaying of STL ASCII and Binary File

2014 ◽  
Vol 940 ◽  
pp. 433-436 ◽  
Author(s):  
Ying Zhang ◽  
Xin Shi
Keyword(s):  
Detailed Analysis ◽  
Programming Language ◽  
Coordinate Transformation ◽  
Graphical Representation ◽  
Three Dimensional ◽  
File Format ◽  
Binary File ◽  
Stl File ◽  
File Formats ◽  
Three Dimensional Display

Based on the detailed analysis of the STL file format, VC++ 6.0 programming language was used to extract the STL ASCII and binary file information, at the same time, using the OpenGL triangle drawing technology for graphical representation of the STL file, with rendering functions such as material, coordinate transformation, lighting, et al, finally realizing the loading and three-dimensional display of STL ASCII and binary file formats.

Handling Blending Features in Form Feature Recognition Using Convex Decomposition

1994 ◽  
Author(s):  
Sreekumar Menon ◽  
Yong Se Kim
Keyword(s):  
Feature Recognition ◽  
Boundary Representation ◽  
Recognition Method ◽  
Geometric Information ◽  
Polyhedral Model ◽  
Curved Boundary ◽  
Convex Decomposition ◽  
Geometric Objects ◽  
Form Features ◽  
Form Feature

Abstract Form features intrinsic to the product shape can be recognized using a convex decomposition called Alternating Sum of Volumes with Partitioning (ASVP). However, the domain of geometric objects to which ASVP decomposition can be applied had been limited to polyhedral solids due to the difficulty of convex hull construction for solids with curved boundary faces. We develop an approach to extend the geometric domain to solids having cylindrical and blending features. Blending surfaces are identified and removed from the boundary representation of the solid, and a polyhedral model of the unblended solid is generated while storing the cylindrical geometric information. From the ASVP decomposition of the polyhedral model, polyhedral form features are recognized. Form feature decomposition of the original solid is then obtained by reattaching the stored blending and cylindrical information to the form feature components of its polyhedral model. In this way, a larger domain of solids can be covered by the feature recognition method using ASVP decomposition. In this paper, handling of blending features in this approach is described.

Geometric Reasoning for the Coding of CAD Models

1995 ◽  
Author(s):  
A. Z. Qamhiyah ◽  
B. Benhabib ◽  
R. D. Venter
Keyword(s):  
Computer Aided Design ◽  
Feature Recognition ◽  
Effective Means ◽  
Boundary Representation ◽  
Cad Model ◽  
Cad System ◽  
Cad Models ◽  
Form Features ◽  
Feature Based Design ◽  
Design Retrieval

Abstract Many of today’s concurrent product-development cycles depend on the utilization of intelligent Computer-Aided Design (CAD) systems. Thus, it would be essential to provide CAD users with effective means for interacting with the CAD system and its database. This paper addresses the development of a boundary-based coding procedure for CAD models. Coding the geometric and processing characteristics of objects, based on their CAD model representation, has been long recognized as an effective approach that allows convenient design retrieval on the one hand and process-planning automation on the other. Our work is based on the assumption that form features are recognizable and extractable from the CAD model by current feature-recognition, feature extraction and feature-based-design approaches. The coding procedure is applicable to the boundary representation of the object and its extracted form features.

Research on Shape Feature Recognition of Boundary Representation CAD Model

2017 ◽  
Vol 14 (1) ◽  
pp. 477-484
Author(s):  
Jihua Wang
Keyword(s):  
Feature Recognition ◽  
Boundary Representation ◽  
Surface Boundary ◽  
Cad Model ◽  
Shape Feature ◽  
Product Model ◽  
Data Files ◽  
Visual Mechanism ◽  
Human Visual Mechanism ◽  
Visual Shape

B-Rep (Boundary Representation) CAD model is being widely used in representation of industrial product, so its feature recognition has acquired widespread research interests in computer vision and 3D model retrieval fields. We present one approach of feature recognition based on the idea of human visual mechanism. Surfaces as the visual shape features, and solids as well as shells as the topological relations, were extracted from the neutral STEP (Standard for Exchange of Product Model Data) files of B-Rep model. Towards three surface types of NURBS, analytical and poly loop, the properties of surface boundary and region are established based on curvature and other geometric index. So B-Rep CAD model is characterized as the hierarchical tree with solid layer, shell layer and surface layer for object recognition and retrieval, and the corresponding experiments verified the effectiveness of the method of shape feature recognition.

A Feature Recognition Approach with Fuzzy ART Neural Network

2011 ◽  
Vol 279 ◽  
pp. 406-411
Author(s):  
Cong Lu ◽  
Jun Zha
Keyword(s):  
Neural Network ◽  
Feature Recognition ◽  
Boundary Representation ◽  
Solid Model ◽  
Fuzzy Art ◽  
Fast Learning ◽  
Key Technologies ◽  
Learning Modes ◽  
Slow Learning

This paper proposes a feature recognition approach from a boundary representation solid model with Fuzzy ART neural network. To recognize the feature efficiently, some key technologies in Fuzzy ART neural network are used. The influence of the vigilance parameter on feature recognition is studied, and two learning modes, fast learning and slow learning are adopted and compared in feature recognition. Finally, a case study is given to verify the proposed approach.

scholarly journals STL file format MeshIO class for ITK

2014 ◽  
Author(s):  
Luis Ibanez
Keyword(s):  
Input Data ◽  
Source Code ◽  
Fundamental Principle ◽  
File Format ◽  
Output Data ◽  
Scientific Publications ◽  
Reading And Writing ◽  
Stl File ◽  
3D Space

This document describes the implementation of an ITK class to support the reading and writing of Meshes in STL file format. The Meshes are assumed to contain 2D manifolds embedded in a 3D space. In practice, it would be desirable to use this class mostly to read and write QuadEdgeMeshes.This paper is accompanied with the source code, input data, parameters and output data that the authors used for validating the algorithm described in this paper. This adheres to the fundamental principle that scientific publications must facilitate reproducibility of the reported results.

Augmented Convex Decomposition Using Incremental Update for Recognition of Form Features

1996 ◽  
Author(s):  
Frédéric Parienté ◽  
Yong Se Kim
Keyword(s):  
Feature Recognition ◽  
Feature Representation ◽  
Boundary Representation ◽  
Central Feature ◽  
Decomposition Tree ◽  
Active Components ◽  
Convex Decomposition ◽  
Volumetric Representation ◽  
Incremental Update ◽  
Form Features

Abstract Alternating Sum of Volumes with Partitioning (ASVP) decomposition is a volumetric representation of a part obtained from its boundary representation that organizes faces of the part in an outside-in hierarchy. ASVP decomposition combines Alternating Sum of Volumes (ASV) decomposition, using convex hulls and set difference operations, and remedial partitioning, using cutting operations and concave edges. A Form Feature Decomposition (FFD) which can serve as a central feature representation for various applications is obtained from ASVP decomposition. The incremental update of convex decomposition is achieved by exploiting its hierarchical structure. For a connected incremental design change, the active components that only need to be updated are localized in a subtree of the decomposition tree called active subtree. Then, the new decomposition is obtained by only updating the active subtree in the old decomposition. In this paper, we present a new decomposition, called Augmented Alternating Sum of Volumes with Partitioning (AASVP) decomposition, that is incrementally constructed using ASV incremental update as a local operation on a decomposition tree. AASVP provides an improved feature recognition capability as it localizes the effect of the change in the decomposition tree, avoids excessive remedial partitioning and catches the designer’s intent in feature editing. AASVP differs from ASVP at the remedial-partitioning nodes by partitioning less. The current remedial partitioning method could be improved such that AASVP decomposition can be constructed directly from the solid model.

scholarly journals Cell Entry of the Aphthovirus Equine Rhinitis A Virus Is Dependent on Endosome Acidification

2010 ◽  
Vol 84 (12) ◽  
pp. 6235-6240 ◽  
Author(s):  
Elisabetta Groppelli ◽  
Tobias J. Tuthill ◽  
David J. Rowlands
Keyword(s):  
Disease Virus ◽  
Foot And Mouth Disease ◽  
Model System ◽  
Dominant Negative ◽  
Cell Entry ◽  
Attractive Alternative ◽  
Pharmacological Agents ◽  
Early Endosomes ◽  
Mouth Disease Virus ◽  
The Family

ABSTRACT Equine rhinitis A virus (ERAV) is genetically closely related to foot-and-mouth disease virus (FMDV), and both are now classified within the genus Aphthovirus of the family Picornaviridae. For disease security reasons, FMDV can be handled only in high-containment facilities, but these constraints do not apply to ERAV, making it an attractive alternative for the study of aphthovirus biology. Here, we show, using immunofluorescence, pharmacological agents, and dominant negative inhibitors, that ERAV entry occurs (as for FMDV) via clathrin-mediated endocytosis and acidification of early endosomes. This validates the use of ERAV as a model system to study the mechanism of cell entry by FMDV.

Feature Recognition for Virtual Environments

2014 ◽  
Vol 610 ◽  
pp. 642-646
Author(s):  
Mong Heng Ear ◽  
Cheng Cheng ◽  
Salem Mostafa Hamdy ◽  
Alhazmi Marwah
Keyword(s):  
Virtual Environments ◽  
Data Exchange ◽  
Feature Recognition ◽  
Virtual Assembly ◽  
Recognition Algorithm ◽  
Boundary Representation ◽  
Adjacency Graph ◽  
Levels Of Detail ◽  
Data Source ◽  
Design Systems

This paper demonstrates methods to recognize 3D designed features for virtual environments and apply them to Virtual assembly. STEP is a standard of Product data Exchange for interfacing different design systems, but it cannot be used as input for virtual environments. In order to use feature data in virtual assembly environments, main data source from a STEP file should be recognized and features should be re-built. First, Attributed Adjacency Graph (AAG) is used to analyze and express the boundary representation; second, a feature-tree of a part is constructed; third, using the AAG and feature-tree as inputs, we analyze and extract of features with a feature recognition algorithm; finally, various levels of detail of object geometric shapes is built and expressed in XML for virtual assembly applications.

scholarly journals Design and Fabrication of 3-DOF Robot Arm Using Parallelogram Mechanisms

2021 ◽  
Vol 9 (9) ◽  
pp. 1224-1229
Keyword(s):  
Robotic Arm ◽  
Robot Motion ◽  
3D Printer ◽  
File Format ◽  
Robot Arm ◽  
End Effector ◽  
Stl File ◽  
Stepper Motors ◽  
And Control

This paper focuses on the design, fabrication and control of a 3-DOF robot arm using stepper motors. The robot arm uses three parallelogram mechanisms to position the end-effector of the robot and keep the end-effector always parallel to the horizontal during the robot motion. The robot is designed on the Autodesk Inventor software. Separated parts of the robot are saved in the stereolithography (STL) file format. Then the parts are fabricated by a 3D printer. The movement of the robotic arm is driven by stepper motors and controlled by Arduino. The Arduino board implements kinematics calculation, creates pulses and sends them to three drivers to driven stepper motors. A software is developed to control the robot by sending the command to the Arduino board.

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