tetgen

tetgen, a C++ code which creates a 3D mesh of tetrahedrons, suitable for use in finite element or finite volume calculations, with the mesh satisfying the 3D Delaunay criterion. The program is by Hang Si.

For a 3D point set, the program generates the Delaunay tetrahedralization and the convex hull.

For a 3D domain, in which the user has defined boundaries, the program can generate additional internal points, which are then organized into a boundary-constrained conforming quality Delaunay mesh.

tetgen works with the following files:

• .node, (input/output), a list of nodes;
• .poly, (input), a piecewise linear complex;
• .smesh, (input/output), a simple piecewise linear complex;
• .ele, (input/output), a list of tetrahedral elements;
• .face, (input/output), a list of triangular faces;
• .edge, (output), a list of boundary edges;
• .vol, (input), a list of maximum volumes;
• .var, (input), a list of variant constraints for facets or segments;
• .neighb (output), a list of neighbors;

tetgen can read and write the following common polyhedral file formats:

• .mesh, (input/output), Medit's surface mesh file format;
• .off, (input/output), the polyhedral file format for Geomview;
• .ply, (input), a polyhedral file format;
• .stl, (input), the stereolithography file format;

Licensing:

The information on this web page is distributed under the MIT license.

Related Data and Programs:

BAMG, examples which illustrate the use of BAMG, a program for generating 2D meshes that can be used to define the geometry for the the finite element package FREEFEM++.

DIST_PLOT, a MATLAB program which creates a color contour plot of the distance functions that are used by DISTMESH.

DISTMESH, a MATLAB library which creates meshes, for 2D or 3D data.

DISTMESH_3D, a MATLAB program which is a subset of the DISTMESH routines, exclusively for 3D problems.

GMSH, examples which illustrate the use of the gmsh program, a 3D mesh generator for the finite element method (FEM).

MESH, a data directory which contains examples of MESH files, which can be used to define the geometry of a finite element mesh in 2D or 3D, using triangles, quadrilaterals, tetrahedrons or hexahedrons. These files can be viewed by the medit graphics program.

MESH2D, a MATLAB library which can automatically create a triangular mesh for a given polygonal region, by Darren Engwirda.

OFF, a data directory which contains examples of Object File Format (OFF) files, a Geomview file format for 3D graphics;

PLY, a data directory which contains examples of PLY files, a format for objects defined as a collection of polygons, 3D graphics;

POLY_3D, a data directory which contains examples of 3D POLY files, a 3D format used by tetgen and tetview, for a Piecewise Linear Complex.

STLA, a data directory which contains examples of ASCII stereolithography (STL) files for 3D graphics;

TETVIEW, examples of the use of TETVIEW which can display the 3D meshes and tetrahedralizations created by TETGEN.

Author:

Hang Si

Reference:

1. G Miller, D Talmor, S-H Teng, N Walkington, H Wang,
   Control volume meshes using sphere packing: generation, refinement and coarsening,
   Proceedings of the Fifth International Meshing Roundtable,
   pages 47-61, 1996.
2. Hang Si,
   TetGen: A Quality Tetrahedral Mesh Generator and 3D Delaunay Trianulator,
   Version 1.4 User Manual,
   Weierstrass Institute for Applied Analysis and Stochastics (WIAS),
   16 January 2006.
3. Hang Si,
   TetGen, a Delaunay-based quality tetrahedral mesh generator,
   ACM Transactions on Mathematical Software,
   Volume 41, Number 2, January 2015, 36 pages.

Examples and Tests:

CUBE starts with a "poly" file that describes a cube.

• cube.poly

• cube.1.ele, the mesh elements.
• cube.1.face, the mesh faces.
• cube.1.node, the mesh nodes.

ELLELL starts with a "ply" file that describes a building with L-shaped base and profile.

• ellell.ply

• ellell.1.ele, the mesh elements.
• ellell.1.face, the mesh faces.
• ellell.1.node, the mesh nodes.
• ellell.1.png, a mesh image from tetview.

• ellell.2.ele, the mesh elements.
• ellell.2.face, the mesh faces.
• ellell.2.node, the mesh nodes.
• ellell.2.png, a mesh image from tetview.

EXAMPLE starts with just a "poly" file that describes a compensated magic tee junction, with 54 nodes and 29 faces. The poly file describes a piecewise linear complex (PLC).

• example.poly

The command tetgen -pg example reads the PLC, and writes its constrained Delaunay tetrahedralization to node, element and face files. The additional "g" switch creates a ".mesh" file which can be used by the MEDIT graphics program.

• example.poly
• example.1.mesh
• example.1.png, a snapshot of the region taking while viewing the mesh file with Medit.
• example.1.node
• example.1.ele
• example.1.face
• example.1.output.txt, the output file.

The command tetgen -pgq example reads the PLC and creates a quality mesh, with a quality ratio (circumradius to shortest edge) bounded by 2.0 (the default). The additional "g" switch creates a ".mesh" file which can be used by the MEDIT graphics program.

• example.poly
• example.1.mesh
• example.1.png, a snapshot of the region taking while viewing the mesh file with Medit.
• example.1.node
• example.1.ele
• example.1.face
• example.1.output.txt, the output file.

The command tetgen -pgq1.414V example forces the quality ratio to be bounded by 1.414. The additional "g" switch creates a ".mesh" file which can be used by the MEDIT graphics program.

• example.poly
• example.1.mesh
• example.1.png, a snapshot of the region taking while viewing the mesh file with Medit.
• example.1.node
• example.1.ele
• example.1.face
• example.1.output.txt, the output file.

Creating a "node" file, the command tetgen example now simply computes the Delaunay tetrahedralization and the convex hull of the given nodes.

• example.node
• example.1.node
• example.1.ele
• example.1.face
• example.1.output.txt, the output file.

You can go up one level to the Examples directory.