TRIANGLE_FILES is a data directory which contains some examples of the groups of files used by the TRIANGLE and SHOWME programs to produce triangulations and Voronoi decompositions of a region.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
POLY, a data directory which contains examples of POLY files, a 2D format used by triangle and showme for Planar Straight Line Graphs.
SHOWME, a C program which uses the X Window library to display triangulatons, by Jonathan Shewchuk.
TRIANGLE, a C program which computes a triangulation of a geometric region, by Jonathan Shewchuk.
TRIANGLE_DISPLAY, a MATLAB program which displays the nodes and elements of a triangulation on the MATLAB graphics screen, assuming the data has been stored in NODE and ELE files by the TRIANGLE program.
A is a planar straight line graph of the capital letter A. We use it as input to get a constrained Delaunay triangulation.
AIRFOIL_EXTERIOR defines the boundary of an airfoil, and a box. We want to mesh the region inside the box and exterior to the airfoil. We use the command
triangle -a0.05 airfoil_exterior.poly
AIRFOIL_INTERIOR defines the boundary of an airfoil, whose interior we want to mesh. We use the command
triangle -a0.05 airfoil_interior.poly
BOX is a planar straight line graph of a double box. We use it as input to get a constrained Delaunay triangulation.
DIAMOND_02_00009 is another set of test data, for which we want the Voronoi diagram.
DOUBLE_HEX describes a unit square with two hexagonal holes. 72 points are listed on the outer boundary, and 12 on each of the holes. It is desired to create a nice looking mesh of about 500 nodes, and no additional nodes on the boundary segments.
triangle -p double_hex.polyrequests that we triangulate the current points:
triangle -pqY -a0.0015 double_hex.1.polyrequests that we triangulate the current points, adding new nodes as necessary to make a nice mesh, with no triangle being larger than 0.0015 in area, and with no points added on boundary segments. We end up with 525 nodes and 956 elements:
DOUBLE_HEX2 describes a unit square with two hexagonal holes. 36 points are listed on the outer boundary, and 6 on each of the holes. It is desired to create a nice looking mesh of about 235 elements, and no additional nodes on the boundary segments.
triangle -p double_hex2.polyrequests that we triangulate the current points:
triangle -pqY -a0.0060 double_hex2.1.polyrequests that we triangulate the current points, adding new nodes as necessary to make a nice mesh, with no triangle being larger than 0.0060 in area, and with no points added on boundary segments. We end up with 141 nodes and 236 elements:
DOUBLE_HEX3 describes a unit square with two hexagonal holes. 4 points are listed on the outer boundary, and 6 on each of the holes. We want triangle to triangulate this region.
triangle -pq -a0.0015 double_hex3.polyrequests that we triangulate the region, adding points as necessary so that no triangle has an area greater than 0.0015.
ELL is a triangulation of an L-shaped region, using a mesh of 21 nodes and 24 elements.
GREENLAND is a triangulation of Greenland, using a graded (varying-size) mesh of 33,343 nodes and 64,125 elements. The resulting image is essentially a red blob the shape of Greenland. However, using the ZOOM tool, it is possible to see interesting details of the mesh.
LA is a POLY file containing information representing soil layers. The data includes points that are bounded by line segments defining the different layers. The intent is that certain layers will be triangulated with smaller area requirements.
SPIRAL is a node file containing points that form a spiral.
SQUARE_CIRCLE_HOLE is a planar straight line graph of a square region with an off center circular hole, and 826 points computed by a CVT calculation, prepared by Hua Fei.
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