CGAL 5.6.3 - Surface Mesh

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Functions
I/O Functions (OFF)
Surface Mesh Reference » I/O Functions

##

I/O Functions for the Object File Format (OFF).

## Functions
template<typename Point , typename NamedParameters = CGAL::parameters::Default_named_parameters>
bool | CGAL::IO::read_OFF (std::istream &is, Surface_mesh< Point > &sm, const NamedParameters &np=parameters::default_values())
| extracts the surface mesh from an input stream in the Object File Format (OFF) and appends it to the surface mesh `sm`.
template<typename Point , typename NamedParameters = CGAL::parameters::Default_named_parameters>
bool | CGAL::IO::write_OFF (std::ostream &os, const Surface_mesh< Point > &sm, const NamedParameters &np=parameters::default_values())
| writes the surface mesh `sm` in the output stream, using the Object File Format (OFF).

## Function Documentation

## ◆ read_OFF()

template<typename Point , typename NamedParameters = CGAL::parameters::Default_named_parameters>

bool CGAL::IO::read_OFF | ( | std::istream & | is,
|  | Surface_mesh< Point > & | sm,
|  | const NamedParameters & | np = `parameters::default_values()`
| ) |  |

`#include <CGAL/Surface_mesh/IO/OFF.h>`

extracts the surface mesh from an input stream in the Object File Format (OFF) and appends it to the surface mesh `sm`.

This function reads points, as well as vertex normals, vertex and face colors, and texture vertex coordinates if those attributes are available in the input. These last four attributes are stored in internal property maps of `sm` named "v:normal", "v:color", "f:color", and `"v:texcoord"`, respectively, which will be created if they do not already exist. If property maps are passed through named parameters (see below), then they are used instead of the internal ones.

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Attention
  The graph `sm` is not cleared, and the data from the stream is added.

Template Parameters

  Point | The type of the point property of a vertex. There is no requirement on `P`, besides being default constructible and assignable. In typical use cases it will be a 2D or 3D point type.
  NamedParameters | a sequence of Named Parameters

Parameters

  is | the input stream
  sm | the surface mesh to be constructed
  np | optional Named Parameters described below

Optional Named Parameters

  a property map associating points to the vertices of `sm` Type: a class model of `WritablePropertyMap` with `Surface_mesh::Vertex_index` as key type and `Point` as value type Default: `boost::get(CGAL::vertex_point, g)` |
  a property map associating normals to the vertices of `sm` Type: a class model of `WritablePropertyMap` with `Surface_mesh::Vertex_index` as key type and a 3D vector type issued from the same kernel as `Point` as value type Default: If this parameter is unused, vertex normals (if they exist) will be written in an internal property map called `v:normal`. |
  a property map associating colors to the vertices of `sm` Type: a class model of `WritablePropertyMap` with `Surface_mesh::Vertex_index` as key type and `CGAL::IO::Color` as value type Default: If this parameter is unused, vertex colors (if they exist) will be written in an internal property map called `v:color`. |
  a property map associating textures to the vertices of `sm` Type: a class model of `WritablePropertyMap` with `Surface_mesh::Vertex_index` as key type and a 2D vector type issued from the same kernel as `Point` as value type Default: If this parameter is unused, vertex textures (if they exist) will be written in an internal property map called `v:texcoords`. |
  a property map associating colors to the faces of `sm` Type: a class model of `WritablePropertyMap` with `Surface_mesh::Face_index` as key type and `CGAL::IO::Color` as value type Default: If this parameter is unused, face colors (if they exist) will be written in an internal property map called `f:color`. |

Precondition
  The data in the stream must represent a two-manifold. If this is not the case the `failbit` of `is` is set and the mesh cleared.

## ◆ write_OFF()

template<typename Point , typename NamedParameters = CGAL::parameters::Default_named_parameters>

bool CGAL::IO::write_OFF | ( | std::ostream & | os,
|  | const Surface_mesh< Point > & | sm,
|  | const NamedParameters & | np = `parameters::default_values()`
| ) |  |

`#include <CGAL/Surface_mesh/IO/OFF.h>`

writes the surface mesh `sm` in the output stream, using the Object File Format (OFF).

This overload of `write_OFF(std::ostream&, const Graph&)` will also output the following property maps internal to the surface mesh, if they exist and if they are not already present in the named parameters:

- vertex normals (property map named "v:normal" in the surface mesh)
- vertex colors (property map named "v:color" in the surface mesh)
- vertex textures (property map named "v:texcoord" in the surface mesh)
- face colors (property map named "f:color" in the surface mesh)

Template Parameters

  Point | The type of the point property of a vertex. There is no requirement on `P`, besides being default constructible and assignable. In typical use cases it will be a 2D or 3D point type.
  NamedParameters | a sequence of Named Parameters

Parameters

  os | the output stream
  sm | the surface mesh to be output
  np | optional Named Parameters described below

Optional Named Parameters

  a property map associating points to the vertices of `sm` Type: a class model of `ReadablePropertyMap` with `Surface_mesh::Vertex_index` as key type and `Point` as value type Default: `boost::get(CGAL::vertex_point, g)` |
  a property map associating normals to the vertices of `sm` Type: a class model of `ReadablePropertyMap` with `Surface_mesh::Vertex_index` as key type and a 3D vector type issued from the same kernel as `Point` as value type Default: vertex normals will be output using the internal property map, if it exists. |
  a property map associating colors to the vertices of `sm` Type: a class model of `ReadablePropertyMap` with `Surface_mesh::Vertex_index` as key type and `CGAL::IO::Color` as value type Default: vertex colors will be output using the internal property map, if it exists. |
  a property map associating textures to the vertices of `sm` Type: a class model of `ReadablePropertyMap` with `Surface_mesh::Vertex_index` as key type and a 2D point type issued from the same kernel as `Point` as value type Default: vertex textures will be output using the internal property map, if it exists. |
  a property map associating colors to the faces of `sm` Type: a class model of `ReadablePropertyMap` with `Surface_mesh::Face_index` as key type and `CGAL::IO::Color` as value type Default: face colors will be output using the internal property map, if it exists. |
  a parameter used to set the precision (i.e. how many digits are generated) of the output stream Type: int Default: the precision of the stream `os` |

Returns
  `true` if writing was successful, `false` otherwise.