Rapid prototyping through scanned point data

Rapid prototyping (RP) is an emerging, non-traditional fabrication method and has been recognized as a valid tool to shorten the lead-time from design to manufacture effectively. Most of the current RP systems adopt the triangular meshes of stereolithoraphy (STL) as a standard format for data input. Thus, the construction of triangular meshes directly affects the quality of RP parts and their subsequent processes. Traditionally, STL data are output from 3D CAD models built using commercial 3D CAD/CAM software packages. This study, however, differs from the traditional way in that it generates the STL data directly from scanned 3D data points, thus preventing various problems associated with 3D CAD modelling from a large quantity of data points. Specific tasks involved in this study include: (1) development of the methodology to convert massive data points into numerous, connected triangular meshes, (2) determination of unit normal vector for each triangular mesh facet, (3) output of triangular meshes with normal vectors in STL format, and (4) slicing of triangular-mesh model into a series of 2D sections.

[1]  S. Rippa.  Long and thin triangles can be good for linear interpolation , 1992 .

[2]  Paul S. Heckbert,et al.  Survey of Polygonal Surface Simplification Algorithms , 1997 .

[3]  William H. Frey,et al.  An apporach to automatic three‐dimensional finite element mesh generation , 1985 .

[4]  Nira Dyn,et al.  Algorithms for the construction of data dependent triangulations , 1990 .

[5]  Larry L. Schumaker,et al.  Computing optimal triangulations using simulated annealing , 1993, Comput. Aided Geom. Des..

[6]  Barry Hilary Valentine Topping,et al.  Finite Element Mesh Generation , 2002 .

[7]  A. Bykat,et al.  Design of a recursive, shape controlling mesh generator , 1983 .

[8]  Bernd Hamann,et al.  On Simulated Annealing and the Construction of Linear Spline Approximations for Scattered Data , 2001, IEEE Trans. Vis. Comput. Graph..

[9]  Hans Hagen,et al.  Geometric surface patches without twist constraints , 1986, Comput. Aided Geom. Des..

[10]  Michael Margaliot,et al.  Piecewise-linear surface approximation from noisy scattered samples , 1994, Proceedings Visualization '94.

[11]  Roni Yagel,et al.  Octree-based decimation of marching cubes surfaces , 1996, Proceedings of Seventh Annual IEEE Visualization '96.

[12]  J. Cavendish.  Automatic triangulation of arbitrary planar domains for the finite element method , 1974 .

[13]  D. T. Lee,et al.  Two algorithms for constructing a Delaunay triangulation , 1980, International Journal of Computer & Information Sciences.

[14]  Jeffrey L. Brown,et al.  Vertex based data dependent triangulations , 1991, Comput. Aided Geom. Des..

[15]  E. F. D’Azevedo,et al.  Optimal Triangular Mesh Generation by Coordinate Transformation , 1991, SIAM J. Sci. Comput..

[16]  Ethan D. Bloch.  A First Course in Geometric Topology and Differential Geometry , 1996 .

[17]  G. Nielson.  The side-vertex method for interpolation in triangles☆ , 1979 .

[18]  William E. Lorensen,et al.  Marching cubes: A high resolution 3D surface construction algorithm , 1987, SIGGRAPH.

[19]  A. O. Moscardini,et al.  AGTHOM-automatic generation of triangular and higher order meshes , 1983 .

[20]  Les A. Piegl,et al.  Algorithm for Delaunay triangulation and convex-hull computation using a sparse matrix , 1992, Comput. Aided Des..

[21]  Li Shi.  AUTOMATIC TRIANGULATION OF ARBITRARY PLANAR DOMAIN , 2000 .

[22]  Y. Yoon,et al.  Triangulation of scattered data in 3D space , 1988 .

[23]  Larry L. Schumaker,et al.  Least Squares Fitting by Linear Splines on Data Dependent Triangulations , 1991, Curves and Surfaces.

[24]  W. Thacker,et al.  A method for automating the construction of irregular computational grids for storm surge forecast models , 1980 .

[25]  Leila De Floriani,et al.  Delaunay-based representation of surfaces defined over arbitrarily shaped domains , 1985, Comput. Vis. Graph. Image Process..