TetgenSetupAndUsage

Setup:
    cd <tetgen-directory>
    mkdir build
    cd build
    cmake ..
    make
    
Usage:
1............................ HELP ....
    ./tetgen -h 
        // to get the list of options and help
    
    
2............................ GENEARATE TETRAHEDRAL MESH [DEFAULT]....
    ./tetgen -p example.poly

        // With the -p switch, TetGen will read the file, i.e., example.poly, 
        and generate its constrained Delaunay tetrahedralization. 
        The resulting mesh is saved in four files: example.1.node, 
        example.1.ele, example.1.face, and example.1.edge, which are a list 
        of mesh nodes, tetrahedra, boundary faces, and boundary edges, 
        respectively. The file formats of TetGen are described in Section 5. 

        
3............................ GENEARATE TETRAHEDRAL MESH [FINER] ....
        // The above mesh is pretty coarse, and contains many badly-shaped 
        (e.g., long and skinny) tetrahedra. Now try:

    tetgen -pq example.poly

        // The -q switch triggers the mesh refinement such that Steiner points 
        are added to remove badly-shaped tetrahedra. The resulting mesh is 
        contained in the same four files as before. However, now it is a 
        quality tetrahedral mesh whose tetrahedra have no small face angle 
        less than about 14o (the default quality value). 

4............................ GENEARATE TETRAHEDRAL MESH [FINER + MORE CONTROL 
                                + MESH QUALITY REPORT] ....
    tetgen -pq1.2V example.poly

        // TetGen will again generate a quality mesh, which contains 
        more points than the previous one, and all tetrahedra have 
        radius-edge ratio bounded by 1.2, i.e., the element shapes are better 
        than those in the previous mesh. In addition, TetGen prints a mesh 
        quality report (due to the -V switch)

5............................ GENEARATE TETRAHEDRAL MESH [FINER + MORE CONTROL 
                                + MESH QUALITY REPORT + VOLUME CONSTRAINT] .... 
        // Instead of using the -q switch to get a finer mesh, one can use the 
        -a switch to impose a maximum volume constraint on the resulting 
        tetrahedra. By doing so, no tetrahedron in the resulting mesh has 
        volume bigger than the specified value after -a. Try to run the 
        following command.

    tetgen -pq1.2Va1 example.poly

        // Now the resulting mesh should contain much more vertices than the 
        previous one. Besides of -q and -a switches, TetGen provides more 
        switches to control the mesh element size and shape. They are described 
        in Section 4. 

6............................ OUTPUT AND VISUALIZATION ....
    tetgen output format description: 
        http://wias-berlin.de/software/tetgen/1.5/doc/manual/manual006.html#sec%3Aff
        http://wias-berlin.de/software/tetgen/1.5/fformats.examples.html
        
    Use tetview to visualize the result.. alternatively you can use Medit..
    
    IMPORTANT: https://www.ljll.math.upmc.fr/frey/software.html
    
    For viewing mesh under Medit, add a -g switch in the command line. TetGen 
    will additionally output a file named example.1.mesh, which can be read and 
    rendered directly by TetGen. Try running:

    tetgen -pg example.poly
    medit example.1

7.............................. TLDR ....
    Run this:
    Mesh Generation:
        ./tetgen -pgq1.2Va0.0625 ../meshes/example_poly/example.poly
    Visualize:
        ./medit-2.3-linux ../meshes/example_poly/example.1.mesh