I/O Functions

Methods to read and write graphs.

Topics
	STL I/O Functions
	I/O Functions for the IOStreamSTL.
	PLY I/O Functions
	I/O Functions for the IOStreamPLY.
	OBJ I/O Functions
	I/O Functions for the IOStreamOBJ.
	OM I/O Functions
	I/O Functions for the IOStreamOM.
	OFF I/O Functions
	I/O Functions for the IOStreamOFF.
	VTP I/O Functions
	I/O Functions for the IOStreamVTK.
	GOCAD I/O Functions
	I/O Functions for the IOStreamGocad.
	WRL I/O Functions
	I/O Functions for the IOStreamWRL.
	3MF I/O Functions
	I/O Functions for the IOStream3MF.
	I/O Functions (Deprecated)

Functions
template<class Graph , typename NamedParameters = parameters::Default_named_parameters>
bool	CGAL::IO::read_polygon_mesh (const std::string &fname, Graph &g, const NamedParameters &np=parameters::default_values())
	reads a polygon mesh from a file.
template<class Graph , typename NamedParameters = parameters::Default_named_parameters>
bool	CGAL::IO::write_polygon_mesh (const std::string &fname, Graph &g, const NamedParameters &np=parameters::default_values())
	writes a polygon mesh in a file.

Function Documentation

read_polygon_mesh()

template<class Graph , typename NamedParameters = parameters::Default_named_parameters>

bool CGAL::IO::read_polygon_mesh	(	const std::string &	fname,
		Graph &	g,
		const NamedParameters &	np = parameters::default_values()
	)

#include <CGAL/IO/polygon_mesh_io.h>

reads a polygon mesh from a file.

Supported file formats are the following:

• IOStreamOFF (.off)
• IOStreamOBJ (.obj)
• IOStreamOM (.om)
• IOStreamSTL (.stl)
• IOStreamPLY (.ply)
• IOStreamGocad (.ts)
• IOStreamVTK (.vtp)

The format is detected from the filename extension (letter case is not important).

The data is expected to represent a 2-manifold (possibly with borders).

Template Parameters

Graph	a model of MutableFaceGraph
NamedParameters	a sequence of Named Parameters

Parameters

fname	the name of the file
g	the mesh
np	optional Named Parameters described below

Optional Named Parameters

vertex_point_map a property map associating points to the vertices of g Type: a class model of WritablePropertyMap with boost::graph_traits<Graph>::vertex_descriptor as key type and Point_3 as value type Default: boost::get(CGAL::vertex_point, g) Extra: If this parameter is omitted, an internal property map for CGAL::vertex_point_t must be available in Graph.
verbose whether extra information is printed when an incident occurs during reading Type: Boolean Default: false

Other named parameters may be used according to the file extension, see I/O Functions for an exhaustive list.

Returns

true if reading was successful, false otherwise.

See also

CGAL::Polygon_mesh_processing::IO::read_polygon_mesh() if the data is not 2-manifold

Examples

BGL_surface_mesh/connected_components.cpp, BGL_surface_mesh/prim.cpp, BGL_surface_mesh/seam_mesh.cpp, BGL_surface_mesh/surface_mesh_dual.cpp, and BGL_surface_mesh/surface_mesh_partition.cpp.

write_polygon_mesh()

template<class Graph , typename NamedParameters = parameters::Default_named_parameters>

bool CGAL::IO::write_polygon_mesh	(	const std::string &	fname,
		Graph &	g,
		const NamedParameters &	np = parameters::default_values()
	)

#include <CGAL/IO/polygon_mesh_io.h>

writes a polygon mesh in a file.

Supported file formats are the following:

• IOStreamOFF (.off)
• IOStreamOBJ (.obj)
• IOStreamSTL (.stl)
• IOStreamPLY (.ply)
• IOStreamGocad (.ts)
• IOStreamVTK (.vtp)

The format is detected from the filename extension (letter case is not important).

Template Parameters

Graph	a model of FaceListGraph and HalfedgeListGraph
NamedParameters	a sequence of Named Parameters

Parameters

fname	the name of the file
g	the mesh to be output
np	optional Named Parameters described below

Optional Named Parameters

vertex_point_map a property map associating points to the vertices of g Type: a class model of ReadablePropertyMap with boost::graph_traits<Graph>::vertex_descriptor as key type and Point_3 as value type Default: boost::get(CGAL::vertex_point, g) Extra: If this parameter is omitted, an internal property map for CGAL::vertex_point_t must be available in Graph.
stream_precision a parameter used to set the precision (i.e. how many digits are generated) of the output stream Type: int Default: 6 Extra: This parameter is only meaningful while using ASCII encoding.
use_binary_mode indicates whether data should be written in binary (true) or in ASCII (false) Type: Boolean Default: true Extra: This parameter is only meaningful for formats that support binary encoding.
verbose whether extra information is printed when an incident occurs during reading Type: Boolean Default: false

Other named parameters may be used according to the file extension, see I/O Functions for an exhaustive list.

Returns

true if writing was successful, false otherwise.

Examples

BGL_surface_mesh/surface_mesh_partition.cpp.