CGAL 5.4  3D Surface Mesh Generation

The concept SurfaceMeshTriangulation_3
describes the triangulation type used by the surface mesher CGAL::make_surface_mesh()
to represent the three dimensional triangulation embedding the surface mesh. Thus, this concept describes the requirements for the triangulation type SurfaceMeshC2T3::Triangulation
nested in the model of SurfaceMeshComplex_2InTriangulation_3
plugged as the template parameter SurfaceMeshC2T3
of CGAL::make_surface_mesh()
. It also describes the requirements for the triangulation type plugged in the class CGAL::Surface_mesh_complex_2_in_triangulation_3<Tr>
.
CGAL::Triangulation_3<TriangulationTraits_3,TriangulationDataStructure_3>
CGAL::Delaunay_triangulation_3<DelaunayTriangulationTraits_3,TriangulationDataStructure_3>
SurfaceMeshComplex_2InTriangulation_3
CGAL::Surface_mesh_complex_2_in_triangulation_3<Tr>
CGAL::make_surface_mesh()
Types  
Vertices and cells of the triangulation are manipulated via handles, which support the two dereference operators and The following iterators allow one to visit all finite vertices, edges and facets of the triangulation.  
typedef unspecified_type  Point 
The point type. More...  
typedef unspecified_type  Vertex_handle 
Handle to a data representing a vertex. More...  
typedef unspecified_type  Cell_handle 
Handle to a data representing a cell. More...  
typedef CGAL::Triple< Cell_handle, int, int >  Edge 
The edge type.  
typedef std::pair< Cell_handle, int >  Facet 
The facet type.  
typedef unspecified_type  Finite_vertices_iterator 
Iterator over finite vertices.  
typedef unspecified_type  Finite_edges_iterator 
Iterator over finite edges.  
typedef unspecified_type  Finite_facets_iterator 
Iterator over finite facets.  
typedef unspecified_type  Geom_traits 
The geometric traits class. More...  
Creation  
SurfaceMeshTriangulation_3 ()  
Default constructor.  
SurfaceMeshTriangulation_3 (SurfaceMeshTriangulation_3 tr)  
Copy constructor. More...  
Assignment  
SurfaceMeshTriangulation_3 &  operator= (const SurfaceMeshTriangulation_3 &tr) 
The triangulation tr is duplicated, and modifying the copy after the duplication does not modify the original. More...  
void  clear () 
Deletes all finite vertices and all cells of t .  
Access Functions  
int  dimension () const 
Returns the dimension of the affine hull.  
const DelaunayTriangulationTraits_3 &  geom_traits () const 
Returns a const reference to a model of DelaunayTriangulationTraits_3 .  
Voronoi diagram  
Object  dual (Facet f) const 
Returns the dual of facet f . More...  
Queries  
A point The set of cells (resp. facets in dimension 2) which are in conflict with  
template<class OutputIteratorBoundaryFacets , class OutputIteratorCells , class OutputIteratorInternalFacets >  
Triple< OutputIteratorBoundaryFacets, OutputIteratorCells, OutputIteratorInternalFacets >  find_conflicts (Point p, Cell_handle c, OutputIteratorBoundaryFacets bfit, OutputIteratorCells cit, OutputIteratorInternalFacets ifit) 
Computes the conflict hole induced by p . More...  
The following iterators allow the user to visit facets, edges and vertices of the triangulation.  
Finite_vertices_iterator  finite_vertices_begin () const 
Starts at an arbitrary finite vertex.  
Finite_vertices_iterator  finite_vertices_end () const 
Pasttheend iterator.  
Finite_edges_iterator  finite_edges_begin () const 
Starts at an arbitrary finite edge.  
Finite_edges_iterator  finite_edges_end () const 
Pasttheend iterator.  
Finite_facets_iterator  finite_facets_begin () const 
Starts at an arbitrary finite facet.  
Finite_facets_iterator  finite_facets_end () const 
Pasttheend iterator.  
template<class OutputIterator >  
OutputIterator  incident_cells (Vertex_handle v, OutputIterator cells) const 
Copies the Cell_handle s of all cells incident to v to the output iterator cells . More...  
bool  is_vertex (const Point &p, Vertex_handle &v) const 
Tests whether p is a vertex of t by locating p in the triangulation. More...  
bool  is_edge (Vertex_handle u, Vertex_handle v, Cell_handle &c, int &i, int &j) const 
Tests whether (u,v) is an edge of t . More...  
bool  is_infinite (const Vertex_handle v) const 
Returns true , iff vertex v is the infinite vertex.  
bool  is_infinite (const Cell_handle c) const 
Returns true , iff c is incident to the infinite vertex. More...  
Facet  mirror_facet (Facet f) const 
Returns the same facet seen from the other adjacent cell.  
int  vertex_triple_index (const int i, const int j) 
Return the indexes of the j th vertex of the facet of a cell opposite to vertex i .  
Point location  
Cell_handle  locate (const Point &query, Cell_handle start=Cell_handle()) const 
If the point query lies inside the convex hull of the points, the cell that contains the query in its interior is returned. More...  
Cell_handle  locate (const Point &query, Locate_type <, int &li, int &lj, Cell_handle start=Cell_handle()) const 
If query lies inside the affine hull of the points, the k face (finite or infinite) that contains query in its interior is returned, by means of the cell returned together with lt , which is set to the locate type of the query (VERTEX, EDGE, FACET, CELL , or OUTSIDE_CONVEX_HULL if the cell is infinite and query lies strictly in it) and two indices li and lj that specify the k face of the cell containing query . More...  
template<class CellIt >  
Vertex_handle  insert_in_hole (Point p, CellIt cell_begin, CellIt cell_end, Cell_handle begin, int i) 
Creates a new vertex by starring a hole. More...  
The geometric traits class.
Must be a model of DelaunayTriangulationTraits_3
.
The point type.
It must be DefaultConstructible, CopyConstructible and Assignable.
SurfaceMeshTriangulation_3::SurfaceMeshTriangulation_3  (  SurfaceMeshTriangulation_3  tr  ) 
Copy constructor.
All vertices and faces are duplicated.
Object SurfaceMeshTriangulation_3::dual  (  Facet  f  )  const 
Returns the dual of facet f
.
In dimension 3: either a segment, if the two cells incident to f
are finite, or a ray, if one of them is infinite;
In dimension 2: a point.
Triple<OutputIteratorBoundaryFacets,OutputIteratorCells,OutputIteratorInternalFacets> SurfaceMeshTriangulation_3::find_conflicts  (  Point  p, 
Cell_handle  c,  
OutputIteratorBoundaryFacets  bfit,  
OutputIteratorCells  cit,  
OutputIteratorInternalFacets  ifit  
) 
Computes the conflict hole induced by p
.
The starting cell (resp. facet) c
must be in conflict.
Then this function returns respectively in the output iterators:
cit
: the cells (resp. facets) in conflict.bfit
: the facets (resp. edges) on the boundary, that is, the facets (resp. edges) (t, i)
where the cell (resp. facet) t
is in conflict, but t>neighbor(i)
is not.ifit
: the facets (resp. edges) inside the hole, that is, delimiting two cells (resp. facets) in conflict.Returns the Triple
composed of the resulting output iterators.
OutputIterator SurfaceMeshTriangulation_3::incident_cells  (  Vertex_handle  v, 
OutputIterator  cells  
)  const 
Copies the Cell_handle
s of all cells incident to v
to the output iterator cells
.
If t.dimension() < 3
, then do nothing. Returns the resulting output iterator.
v != Vertex_handle()
, t.is_vertex(v)
. Vertex_handle SurfaceMeshTriangulation_3::insert_in_hole  (  Point  p, 
CellIt  cell_begin,  
CellIt  cell_end,  
Cell_handle  begin,  
int  i  
) 
Creates a new vertex by starring a hole.
It takes an iterator range [cell_begin, cell_end)
of Cell_handle
s which specifies a hole: a set of connected cells (resp. facets in dimension 2) which is starshaped wrt p
. (begin
, i
) is a facet (resp. an edge) on the boundary of the hole, that is, begin
belongs to the set of cells (resp. facets) previously described, and begin>neighbor(i)
does not. Then this function deletes all the cells (resp. facets) describing the hole, creates a new vertex v
, and for each facet (resp. edge) on the boundary of the hole, creates a new cell (resp. facet) with v
as vertex. Then v>set_point(p)
is called and v
is returned.
t.dimension() >= 2
, the set of cells (resp. facets in dimension 2) is connected, its boundary is connected, and p
lies inside the hole, which is starshaped wrt p
. bool SurfaceMeshTriangulation_3::is_edge  (  Vertex_handle  u, 
Vertex_handle  v,  
Cell_handle &  c,  
int &  i,  
int &  j  
)  const 
Tests whether (u,v)
is an edge of t
.
If the edge is found, it gives a cell c
having this edge and the indices i
and j
of the vertices u
and v
in c
, in this order.
u
and v
are vertices of t
. bool SurfaceMeshTriangulation_3::is_infinite  (  const Cell_handle  c  )  const 
Returns true
, iff c
is incident to the infinite vertex.
t.dimension() == 3
. bool SurfaceMeshTriangulation_3::is_vertex  (  const Point &  p, 
Vertex_handle &  v  
)  const 
Tests whether p
is a vertex of t
by locating p
in the triangulation.
If p
is found, the associated vertex v
is given.
Cell_handle SurfaceMeshTriangulation_3::locate  (  const Point &  query, 
Cell_handle  start = Cell_handle() 

)  const 
If the point query
lies inside the convex hull of the points, the cell that contains the query in its interior is returned.
If query
lies on a facet, an edge or on a vertex, one of the cells having query
on its boundary is returned.
If the point query
lies outside the convex hull of the points, an infinite cell with vertices \( \{ p, q, r, \infty\}\) is returned such that the tetrahedron \( ( p, q, r, query )\) is positively oriented (the rest of the triangulation lies on the other side of facet \( ( p, q, r )\)).
Note that locate works even in degenerate dimensions: in dimension 2 (resp. 1, 0) the Cell_handle
returned is the one that represents the facet (resp. edge, vertex) containing the query point.
The optional argument start
is used as a starting place for the search.
Cell_handle SurfaceMeshTriangulation_3::locate  (  const Point &  query, 
Locate_type &  lt,  
int &  li,  
int &  lj,  
Cell_handle  start = Cell_handle() 

)  const 
If query
lies inside the affine hull of the points, the k
face (finite or infinite) that contains query
in its interior is returned, by means of the cell returned together with lt
, which is set to the locate type of the query (VERTEX, EDGE, FACET, CELL
, or OUTSIDE_CONVEX_HULL
if the cell is infinite and query
lies strictly in it) and two indices li
and lj
that specify the k
face of the cell containing query
.
If the k
face is a cell, li
and lj
have no meaning; if it is a facet (resp. vertex), li
gives the index of the facet (resp. vertex) and lj
has no meaning; if it is and edge, li
and lj
give the indices of its vertices.
If the point query
lies outside the affine hull of the points, which can happen in case of degenerate dimensions, lt
is set to OUTSIDE_AFFINE_HULL
, and the cell returned has no meaning. As a particular case, if there is no finite vertex yet in the triangulation, lt
is set to OUTSIDE_AFFINE_HULL
and locate
returns the default constructed handle.
The optional argument start
is used as a starting place for the search.
SurfaceMeshTriangulation_3& SurfaceMeshTriangulation_3::operator=  (  const SurfaceMeshTriangulation_3 &  tr  ) 
The triangulation tr
is duplicated, and modifying the copy after the duplication does not modify the original.
The previous triangulation held by t
is deleted.