ViennaMesh

Content

Different mesh generation tools support different mesh generation tasks. This examples demonstrates the abstract common interface of ViennaMesh.

Simple API example

SomeDomainType hull_domain;
SomeOtherSomeType volume_domain;
 
viennamesh::resulf_of::settings< some_mesher_tag > settings;
 
viennamesh::run_algo< some_mesher_tag >( hull_domain, volume_domain, settings );

A more concrete example is given below. At first, a PLC file is read (using a TETGEN .poly file). This PLC is meshed to a hull and than further meshed to a volume mesh using a scalar field for the element size.

PLC to Volume Meshing Example

// simple functor for mesh cell size
struct functor
{
    template<typename point_type>
    double operator() (point_type const & p) const
    {  return p[0] / 10.0 * 2.0 + 0.2; }
};
 
int main()
{
  viennagrid::config::plc_3d_domain plc_domain;
 
  // reading a simple cube in the PLC domain
  viennagrid::io::poly_reader reader;
  reader(plc_domain, "cube.poly");
 
  viennagrid::config::triangular_3d_domain triangle_domain;
  // defining the settings for PLC meshing
  viennamesh::result_of::settings<viennamesh::cgal_plc_3d_mesher_tag>::type plc_settings;
    
  // actual PLC -> triangular hull meshing
  viennamesh::run_algo< viennamesh::cgal_plc_3d_mesher_tag >( plc_domain,
                                                          triangle_domain,
                                                          plc_settings );
 
  // defining the settings for tetrahedron volume meshing
  viennamesh::result_of::settings<viennamesh::cgal_delaunay_tetrahedron_tag>::type tet_settings;
    
  // configuring the settings
  functor f;
  tet_settings.cell_size = f;  // assigning functor is possible...
  tet_settings.cell_radius_edge_ratio = 1.5;  // ... as well as simple double values
    
  viennagrid::config::tetrahedral_3d_domain tet_domain;
  // actual triangular hull -> tetrahedron volume meshing
  viennamesh::run_algo<viennamesh::cgal_delaunay_tetrahedron_tag>( triangle_domain,
                                                                  tet_domain, 
                                                                  tet_settings );
 
  // writing output to VTK file
  viennagrid::io::vtk_writer<viennagrid::config::tetrahedral_3d_domain,
                                           viennagrid::config::tetrahedral_3d_cell>
                vtk_volume_writer;
  vtk_volume_writer(tet_domain, "cube_poly_meshed.vtu");    
}