CGAL 4.14 - 3D Mesh Generation
CGAL::Mesh_criteria_3< Tr > Class Template Reference

#include <CGAL/Mesh_criteria_3.h>

## Definition

The class Mesh_criteria_3 is a model of both concepts MeshCriteria_3 and MeshCriteriaWithFeatures_3.

It gathers the refinement criteria for mesh tetrahedra and surface facets where surface facets are facets in the mesh approximating the domain surface patches. In addition, for domain with exposed 1-dimensional features, the class Mesh_criteria_3 handles the definition of a sizing field to guide the discretization of 1-dimensional features.

Template Parameters
 Tr has to be instantiated with the type used for C3T3::Triangulation, where C3T3 is the model of MeshComplex_3InTriangulation_3 used in the mesh generation process, and C3T3::Triangulation its nested triangulation type.
Is Model Of:
MeshCriteria_3

Example

// Create a Mesh_criteria_3<Tr> object with all cell and facet parameters set
Mesh_criteria_3<Tr> criteria (parameters::facet_angle=30,
parameters::facet_size=1,
parameters::facet_distance=0.1,
parameters::cell_size=1.5);
// Create a Mesh_criteria_3<Tr> object with size ignored (note that the order changed)
parameters::facet_angle=30,
parameters::facet_distance=0.1);
MeshCriteria_3
MeshCriteriaWithFeatures_3
MeshCellCriteria_3
MeshEdgeCriteria_3
MeshFacetCriteria_3
MeshDomainField_3
CGAL::Mesh_cell_criteria_3<Tr>
CGAL::Mesh_edge_criteria_3<Tr>
CGAL::Mesh_facet_criteria_3<Tr>
CGAL::Mesh_facet_topology
Examples:
Mesh_3/mesh_3D_gray_image.cpp, Mesh_3/mesh_3D_gray_vtk_image.cpp, Mesh_3/mesh_3D_image.cpp, Mesh_3/mesh_3D_image_variable_size.cpp, Mesh_3/mesh_3D_image_with_custom_initialization.cpp, Mesh_3/mesh_3D_image_with_features.cpp, Mesh_3/mesh_hybrid_mesh_domain.cpp, Mesh_3/mesh_implicit_domains.cpp, Mesh_3/mesh_implicit_domains_2.cpp, Mesh_3/mesh_implicit_ellipsoid.cpp, Mesh_3/mesh_implicit_sphere.cpp, Mesh_3/mesh_implicit_sphere_variable_size.cpp, Mesh_3/mesh_optimization_example.cpp, Mesh_3/mesh_optimization_lloyd_example.cpp, Mesh_3/mesh_polyhedral_complex.cpp, Mesh_3/mesh_polyhedral_domain.cpp, Mesh_3/mesh_polyhedral_domain_with_features.cpp, Mesh_3/mesh_polyhedral_domain_with_lipschitz_sizing.cpp, Mesh_3/mesh_polyhedral_domain_with_surface_inside.cpp, Mesh_3/mesh_two_implicit_spheres_with_balls.cpp, and Mesh_3/remesh_polyhedral_surface.cpp.

## Types

typedef Mesh_edge_criteria_3< Tr > Edge_criteria
The criteria for edges.

typedef Mesh_facet_criteria_3< Tr > Facet_criteria
The criteria for facets.

typedef Mesh_cell_criteria_3< Tr > Cell_criteria
The criteria for cells.

## Creation

Mesh_criteria_3 (const Facet_criteria &facet_criteria, const Cell_criteria &cell_criteria)
Construction from facet and cell criteria. More...

Mesh_criteria_3 (const Edge_criteria &edge_criteria, const Facet_criteria &facet_criteria, const Cell_criteria &cell_criteria)
Construction from edge, facet and cell criteria.

template<typename FT , typename ... Fieldi>
Mesh_criteria_3 (Field1 parameters::edge_size=ignored, FT parameters::facet_angle=ignored, Field2 parameters::facet_size=ignored, Field3 parameters::facet_distance=ignored, Mesh_facet_topology parameters::facet_topology=CGAL::FACET_VERTICES_ON_SURFACE, FT parameters::cell_radius_edge_ratio=ignored, Field4 parameters::cell_size=ignored)
Construction from criteria parameters. More...

## ◆ Mesh_criteria_3() [1/2]

template<typename Tr >
 CGAL::Mesh_criteria_3< Tr >::Mesh_criteria_3 ( const Facet_criteria & facet_criteria, const Cell_criteria & cell_criteria )

Construction from facet and cell criteria.

The edge criteria are ignored in this case.

## ◆ Mesh_criteria_3() [2/2]

template<typename Tr >
template<typename FT , typename ... Fieldi>
 CGAL::Mesh_criteria_3< Tr >::Mesh_criteria_3 ( Field1 parameters::edge_size = ignored, FT parameters::facet_angle = ignored, Field2 parameters::facet_size = ignored, Field3 parameters::facet_distance = ignored, Mesh_facet_topology parameters::facet_topology = CGAL::FACET_VERTICES_ON_SURFACE, FT parameters::cell_radius_edge_ratio = ignored, Field4 parameters::cell_size = ignored )

Construction from criteria parameters.

This constructor uses named parameters (from Boost.Parameter) for convenient criteria construction.

Template Parameters
 FT must be a model of Field Fieldi (i=1,..,4) should be either a model of the concept Field or a model of the concept MeshDomainField_3

The parameters are named parameters and can be passed in any order provided their name is given (see example below). The name of each parameter is the one that is written in the description of the function (e.g. parameters::facet_size).

The description of each parameter is as follows:

• edge_size: a scalar field (resp. a constant) providing a space varying (resp. a uniform) upper bound for the lengths of curve edges. This parameter has to be set to a positive value when 1-dimensional features protection is used.
• facet_angle: a lower bound for the angles (in degrees) of the surface mesh facets.
• facet_size: a scalar field (resp. a constant) describing a space varying (resp. a uniform) upper-bound or for the radii of the surface Delaunay balls.
• facet_distance: a scalar field (resp. a constant) describing a space varying (resp. a uniform) upper bound for the distance between the facet circumcenter and the center of its surface Delaunay ball.
• facet_topology: the set of topological constraints which have to be verified by each surface facet. The default value is CGAL::FACET_VERTICES_ON_SURFACE. See Mesh_facet_topology manual page to get all possible values.
• cell_radius_edge_ratio: an upper bound for the radius-edge ratio of the mesh tetrahedra.
• cell_size: a scalar field (resp. a constant) describing a space varying (resp. a uniform) upper-bound for the circumradii of the mesh tetrahedra.

Note that each size or distance parameter can be specified using two ways: either as a scalar field or as a numerical value when the field is uniform.

Each parameter has a special default value ignored which means that the corresponding criterion will be ignored. Numerical sizing or distance values, as well as scalar fields should be given in the unit used for coordinates of points in the mesh domain class of the mesh generation process.