Constructions for Linear Cell Complex

Basic constructions.

Functions
template<typename LCC = Default, typename TriangleMesh, typename NamedParameters = parameters::Default_named_parameters>
auto	CGAL::generate_hexahedral_mesh_using_two_refinement (const TriangleMesh &tmesh, int cube_cells_per_dim, int nb_levels, const NamedParameters &np=parameters::default_values())
	generates a pure hexahedral mesh from a surface triangle mesh using the two-refinement algorithm described in [1].
template<class LCC>
LCC::Dart_descriptor	CGAL::read_plane_graph_in_lcc (LCC &lcc, std::istream &ais)
	Imports an embedded plane graph read from ais into lcc, a model of the LinearCellComplex concept.
template<class LCC>
LCC::Dart_descriptor	CGAL::import_from_plane_graph (LCC &lcc, std::istream &ais)
template<class LCC, class Polyhedron>
LCC::Dart_descriptor	CGAL::polyhedron_3_to_lcc (LCC &lcc, const Polyhedron &apoly)
	Imports apoly (a Polyhedron_3) into lcc, a model of the LinearCellComplex concept.
template<class LCC, class Triangulation_>
LCC::Dart_descriptor	CGAL::triangulation_3_to_lcc (LCC &lcc, const Triangulation_ &atr)
	Imports atr (a Triangulation_3) into lcc, a model of the LinearCellComplex concept.

Function Documentation

generate_hexahedral_mesh_using_two_refinement()

template<typename LCC = Default, typename TriangleMesh, typename NamedParameters = parameters::Default_named_parameters>

auto CGAL::generate_hexahedral_mesh_using_two_refinement	(	const TriangleMesh &	tmesh,
		int	cube_cells_per_dim,
		int	nb_levels,
		const NamedParameters &	np = parameters::default_values() )

#include <CGAL/Hexmeshing_generate_two_refinement_mesh.h>

generates a pure hexahedral mesh from a surface triangle mesh using the two-refinement algorithm described in [1].

Starts to create a regular grid of cube_cells_per_dim \( ^3\) voxels. Then refines voxels intersected by the surface nb_levels times, while creating transitions between refined and non-refined voxels.

Template Parameters

LCC	the target Linear Cell Complex type, or CGAL::Default.
TriangleMesh	a model of FaceListGraph.
NamedParameters	a sequence of Named Parameters.

Parameters

tmesh	the input triangle mesh.
cube_cells_per_dim	the initial grid resolution per dimension.
nb_levels	the number of two-refinement levels.
np	n optional sequence of Named Parameters among the ones listed below:

Optional Named Parameters

trim_mesh trims exterior mesh elements, i.e., remove volumes that are entirely outside of tmesh Type: bool Default: true
smooth_mesh applies Laplacian smoothing to project boundary vertices onto tmesh Type: bool Default: true

Returns

the resulting linear cell complex representing the hexahedral mesh.

See also

CGAL::Linear_cell_complex_for_combinatorial_map

Examples

Linear_cell_complex/hexmeshing_basic.cpp.

import_from_plane_graph()

template<class LCC>

LCC::Dart_descriptor CGAL::import_from_plane_graph	(	LCC &	lcc,
		std::istream &	ais )

#include <CGAL/Linear_cell_complex_constructors.h>

Deprecated

Use read_plane_graph_in_lcc() instead.

polyhedron_3_to_lcc()

template<class LCC, class Polyhedron>

LCC::Dart_descriptor CGAL::polyhedron_3_to_lcc	(	LCC &	lcc,
		const Polyhedron &	apoly )

#include <CGAL/Polyhedron_3_to_lcc.h>

Imports apoly (a Polyhedron_3) into lcc, a model of the LinearCellComplex concept.

Objects are added in lcc, existing darts are not modified. Returns a dart created during the import.

Precondition

LCC::dimension \( \geq\) 2 and LCC::ambient_dimension==3.

See also

CGAL::read_plane_graph_in_lcc<LCC>

CGAL::triangulation_3_to_lcc<LCC,Triangulation>

read_plane_graph_in_lcc()

template<class LCC>

LCC::Dart_descriptor CGAL::read_plane_graph_in_lcc	(	LCC &	lcc,
		std::istream &	ais )

#include <CGAL/Linear_cell_complex_constructors.h>

Imports an embedded plane graph read from ais into lcc, a model of the LinearCellComplex concept.

Objects are added in lcc, existing darts are not modified. Returns a dart created during the import.

Precondition

LCC::dimension \( \geq\) 2 and LCC::ambient_dimension==2.

File format

The file format must be the following. First the number of vertices and the number of edges of the planar graph. Then, for each vertex of the planar graph, the coordinates of the \( i^{\mbox{th}}\) vertex (two numbers for \( x\) and \( y\) coordinates). The first vertex index is 0. Then for each edge of the planar graph, the two indices of the two vertices (two numbers between 0 and the number of vertices minus 1).

Here a small example:

5 6
1.0 3.0 0.0 2.0 2.0 2.0 0.0 0.0 2.0 0.0
0 1 0 2 1 2 1 3 2 4 3 4

Example of import_graph reading the above file as istream, middle for combinatorial map as combinatorial data-structure, right for generalized maps.

Left: A planar graph embedded in the plane with P0=(1.0,3.0), P1=(0.0,2.0), P2=(2.0,2.0), P3=(0.0,0.0), P4=(2.0,0.0). Middle: the 2D linear cell complex reconstructed if combinatorial maps are the combinatorial data-structure. Right: the 2D linear cell complex reconstructed if generalized maps are the combinatorial data-structure.

See also

CGAL::triangulation_3_to_lcc<LCC,Triangulation>

CGAL::polyhedron_3_to_lcc<LCC,Polyhedron>

triangulation_3_to_lcc()

template<class LCC, class Triangulation_>

LCC::Dart_descriptor CGAL::triangulation_3_to_lcc	(	LCC &	lcc,
		const Triangulation_ &	atr )

#include <CGAL/Triangulation_3_to_lcc.h>

Imports atr (a Triangulation_3) into lcc, a model of the LinearCellComplex concept.

Objects are added in lcc, existing darts are not modified. Returns a dart created during the import.

Precondition

LCC::dimension \( \geq\) 3 and LCC::ambient_dimension==3.

See also

CGAL::read_plane_graph_in_lcc<LCC>

CGAL::polyhedron_3_to_lcc<LCC,Polyhedron>