• Title/Summary/Keyword: Delaunay 삼각형 분할

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STL Generation in Reverse Engineering by Delaunay Triangulation (역공학에서의 Delaunay 삼각형 분할에 의한 STL 파일 생성)

  • Lee, Seok-Hui;Kim, Ho-Chan;Heo, Seong-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.5
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    • pp.803-812
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    • 2002
  • Reverse engineering has been widely used for the shape reconstruction of an object without CAD data and the measurement of clay or wood models for the development of new products. To generate a surface from measured points by a laser scanner, typical steps include the scanning of a clay or wood model and the generation of manufacturing data like STL file. A laser scanner has a great potential to get geometrical data of a model for its fast measuring speed and higher precision. The data from a laser scanner are composed of many line stripes of points. A new approach to remove point data with Delaunay triangulation is introduced to deal with problems during reverse engineering process. The selection of group of triangles to be triangulated based on the angle between triangles is used for robust and reliable implementation of Delaunay triangulation as preliminary steps. Developed software enables the user to specify the criteria for the selection of group of triangles either by the angle between triangles or the percentage of triangles reduced. The time and error for handling point data during modelling process can be reduced and thus RP models with accuracy will be helpful to automated process.

Point Data Reduction in Reverse Engineering by Delaunay Triangulation (역공학에서의 Delaunay 삼각형 분할에 의한 점 데이터 감소)

  • Lee, Seok-Hui;Heo, Seong-Min;Kim, Ho-Chan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.8
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    • pp.1246-1252
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    • 2001
  • Reverse engineering has been widely used for the shape reconstruction of an object without CAD data and the measurement of clay or wood models for the development of new products. To generate a surface from measured points by a laser scanner, typical steps include the scanning of a clay or wood model and the generation of manufacturing data like STL file. A laser scanner has a great potential to get geometrical data of a model for its fast measuring speed and higher precision. The data from a laser scanner are composed of many line stripes of points. A new approach to remove point data with Delaunay triangulation is introduced to deal with problems during reverse engineering process. This approach can be used to reduce a number of measuring data from laser scanner within tolerance, thus it can avoid the time for handling point data during modelling process and the time for verifying and slicing STL model during RP process.

A Study on the Delaunay Triangulation Reconstruction using the Modified EVS (수정된 EVS를 이용한 Delaunay 삼각형 재구성에 관한 연구)

  • Kwon E.C.;Shin D.K.;Kim D.Y.
    • Journal of Biomedical Engineering Research
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    • v.21 no.3
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    • pp.225-231
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    • 2000
  • The Delaunay triangulation. which is one of the surface rendering methods. have been evaluated as a good algorithm which can solve the geometrical connection problems and make high quality images. However this method also have the problem that is the 'non-solid' connection between slices. In this paper, we proposed a new method for the Delaunay triangulation for the surface rendering from 2D medical images in the PC environment. The proposed method was designed to eliminate 'non-solid' tetrahedra. which had no correspondence to the geometric closeness, and used elimination algorithm with modified External Voronoi Skeleton path. This method enabled us to eliminate 'non-solid' tetrahedra without affecting other regions. Thus we could effectively reconstruct the complex shaped objects which were compactly connected with tetrahedra.

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Reverse Engineering of 3D Compound Shapes using Delaunay Triangulation (Delaunay 삼각형분할법을 이용한 3차원복합형상의 역공학)

  • 조승현;조명우;김재도
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.7
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    • pp.181-188
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    • 2000
  • The objective of this research is to develop an efficient reverse engineering method of 3-dimensional compound surfaces for raped prototyping process. As a first step, several image processing techniques were applied to the measured data obtained using laser scanner. And the boundary information of the compound surface were extracted to divide the surface into several separate regions. As a next step, the Delaunay triangulation method were applied to reconstruct the surface based on the measured data and the boundary information. Finally, the STL file were created for the rapid prototyping process. Required simulations and experiments were performed and the results were analyzed to show the effectiveness of the proposed methods.

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System Developement for STL Error Correction and Shape Modification (STL의 오류수정 및 형상수정 시스템의 개발)

  • Chae, Hee-Chang
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.3
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    • pp.53-61
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    • 1999
  • STL has several errors such as orientation error, hole error, and acute triangle error on being translated from CAD software. These errors should be corrected before using in Rapid Prototyping. So the software is necessary to correct errors. In this study, STL Editor which is a system for STL error correction and shape modification is developed and contains following characteristics. 1.Apply the triangle based data st겨cture. 2.Use the graphic user interface for easy work. 3.Use the Diet method to reduce data size. 4.Use the Delaunay triangulation method to enhance the quality of STL. 5.Modify the STL errors manually.

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Application of Delaunay Triangulation on RP (Delaunay삼각형 분할법의 RP에의 응용)

  • 명태식;채희창;김옥현
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.3
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    • pp.35-41
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    • 1999
  • STL which is used in Rapid Prototyping is composed of a lot of triangular facets. The number of triangles and the shapes of these triangles determine the quality of STL. Therefore, proper algorithm is necessary to enhance the quality of triangular patch. In this paper we used the Delaunay triangulation method to apply to following processes. 1) On processing for reducing sharp triangles which cause errors on intersection. 2) On processing for connecting two or more collinear edges. 3) On processing for deleting unnecessarily inserted points in coplanar polygon.

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Delaunay triangulation for efficient reduction of measured point data (측정데이터의 효율적 감소를 위한 De Iaunay 삼각형 분할의 적용)

  • 허성민;김호찬;이석희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.53-56
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    • 2001
  • Reverse engineering has been widely used for the shape reconstruction of an object without CAD data and it includes some steps such as scanning of a clay or wood model, and generating some manufacturing data in an STL file. A new approach to remove point data with Delaunay triangulation is introduced to deal with the size problems of STL file and the difficulties in the operation of RP process. This approach can be used to reduce a number of measuring data from laser scanner within a specified tolerance, thus it can avoid the time for handing point data during modeling process and the time for verifying and slicing STL model during RP process. Developed software enables the user to specify the criteria for the selection of group of triangles either by the angle between triangles or the percentage of triangles reduced, and thus RP models with accuracy will be helpful to automated process.

  • PDF