neuray API Programmer's Manual

mi::neuraylib::IPolygon_mesh Class Reference

[Leaf nodes]

Description

Interface representing a polygon mesh. Polygon meshes are represented in an indexed format where polygons are a finite sequence of indices pointing into an array of points. Points and polygons are stored with consecutive indices, starting with the index 0 each. Both, points and polygons, can then be referred to by their index numbers. For type safety, polygon indices are represented using mi::neuraylib::Polygon_handle instead of plain integers.

This interface provides methods to add points and polygons, and to specify the location of the points. It does not directly provide methods to map the vertices of the polygons to the points. This needs to be done via the polygon connectivity (see edit_mesh_connectivity()).

Polygons with holes can be represented, too. The holes are represented in the same way as polygons themselves, but a flag (see add_polygon()) distinguishes them from the polygons (or more precise, from the outer boundary of polygons). Note that the orientation of holes does not matter.

In addition to regular attributes (see mi::neuraylib::IAttribute_set), meshes can also have mesh attributes. In contrast to regular attributes which exist only once per object, mesh attributes are always a vector of values with one vector element per primitive, per point, or per vertex (see mi::neuraylib::Mesh_attribute_name and mi::neuraylib::IAttribute_vector for details).

Per-primitive attributes can be directly used with the methods of this interface, namely create_attribute_vector(), access_attribute_vector(), edit_attribute_vector(), and attach_attribute_vector().

Per-point and per-vertex attributes require the use of a connectivity instead. Per-point attributes use the mesh connectivity (see edit_mesh_connectivity() and related methods), whereas per-vertex attributes use custom connectivities (see create_connectivity() and related methods).

This mesh interface supports the incremental construction of a mesh. Points and polygons can be added one at a time and in alternating order, if so desired. The only constraint is that polygons shall only refer to point indices of points that have been added already.

The deletion of once added elements is not supported.

See also the "approx" attribute on mi::neuraylib::IAttribute_set for information how to control the tessellation of the polygon mesh.

See also:

mi::neuraylib::IPolygon_connectivity

mi::neuraylib::IAttribute_vector

Example: Create a mesh with a single quad with one normal and four texture coordinates 

‎ // The points of the quad
 mi::Float32_3 point[4];
 point[0] = mi::Float32_3( 0.0f, 0.0f, 0.0f);
 point[0] = mi::Float32_3( 1.0f, 0.0f, 0.0f);
 point[0] = mi::Float32_3( 1.0f, 1.0f, 0.0f);
 point[0] = mi::Float32_3( 0.0f, 0.0f, 0.0f);

 // The normal of the quad
 mi::Float32_3 normal( 0.0f, 0.0f, 1.0f);

 // The texture coordinates for the quad
 mi::Float32_2 tex_coord[4];
 tex_coord[0] = mi::Float32_2( 0.0f, 0.0f);
 tex_coord[0] = mi::Float32_2( 1.0f, 0.0f);
 tex_coord[0] = mi::Float32_2( 1.0f, 1.0f);
 tex_coord[0] = mi::Float32_2( 0.0f, 1.0f);

 mi::base::Handle< mi::neuraylib::IPolygon_mesh> mesh(
     transaction->create<mi::neuraylib::IPolygon_mesh>( "Polygon_mesh"));

 // Create the points of the mesh
 for( mi::Uint32 i = 0; i < 4; ++i)
     mesh->append_point( point[i]);

 // Create the quad and add the mapping of its vertices to points via the mesh connectivity
 mi::neuraylib::Polygon_handle polygon_handle( mesh->add_polygon( 4));
 mi::base::Handle< mi::neuraylib::IPolygon_connectivity> mesh_connectivity(
     mesh->edit_mesh_connectivity());
 mesh_connectivity->set_polygon_indices( polygon_handle, 0, 1, 2, 3);

 // Create an attribute vector for 2-dimensional texture coordinates
 mi::base::Handle< mi::neuraylib::IAttribute_vector> texture_coordinates(
     mesh_connectivity->create_attribute_vector( mi::neuraylib::ATTR_TEXTURE, 2));
 for( mi::Uint32 i = 0; i < 4; ++i)
     texture_coordinates->append_float32( &tex_coord[i].x, 2);
 mesh_connectivity->attach_attribute_vector( texture_coordinates.get());

 // Attach the mesh connectivity back to mesh
 mesh->attach_mesh_connectivity( mesh_connectivity.get());

 // Create a custom connectivity for normals to share the same normal for all vertices
 mi::base::Handle< mi::neuraylib::IPolygon_connectivity> normal_connectivity(
     mesh->create_connectivity( mi::neuraylib::CONNECTIVITY_MAP_GENERIC));
 normal_connectivity->set_polygon_indices( polygon_handle, 0, 0, 0, 0);

 // Create an attribute vector for normals
 mi::base::Handle< mi::neuraylib::IAttribute_vector> normals(
     normal_connectivity->create_attribute_vector( mi::neuraylib::ATTR_NORMAL, 1));
 normals->append_vector3( normal);
 normal_connectivity->attach_attribute_vector( normals.get());

 // Attach the custom connectivity to the mesh
 mesh->attach_connectivity( normal_connectivity.get());
mi::base::Interface_declare\< ..., neuraylib::IPolygon_mesh \>Mixin class template for deriving new interface declarations. mi::base::Interface_declare\< ..., neuraylib::IScene_element \>Mixin class template for deriving new interface declarations. Common base interface for all scene elements.Common base interface for all scene elements. mi::base::Interface_declare\< ..., neuraylib::IAttribute_set \>Mixin class template for deriving new interface declarations. The attribute set comprises all attributes attached to a database element.The attribute set comprises all attributes attached to a database element. mi::base::Interface_declare\< ... \>Mixin class template for deriving new interface declarations. The basic extensible interface.The basic extensible interface. Interface representing a subdivision surface.Interface representing a subdivision surface.

Methods related to points

virtual Uint32 append_point( const Float32_3_struct& p) =0
Adds a point p to the end of all points and returns the index of the new point. More...
virtual Uint32 append_point( const Float64_3_struct& p) =0
Adds a point p to the end of all points and returns the index of the new point. More...
virtual Sint32 point( Uint32 index, Float32_3_struct& p) const =0
Returns the coordinates of the point of index index in the output parameter p. More...
virtual Sint32 point( Uint32 index, Float64_3_struct& p) const =0
Returns the coordinates of the point of index index in the output parameter p. More...
virtual Uint32 points_capacity() const =0
Returns the number of points for which space is allocated in the mesh. More...
virtual Uint32 points_size() const =0
Returns the number of points in the mesh.
virtual void reserve_points( Uint32 n) =0
Reserves space for at least n points. More...
virtual Sint32 set_point( Uint32 index, const Float32_3_struct& p) =0
Sets the point of index index to the new point p. More...
virtual Sint32 set_point( Uint32 index, const Float64_3_struct& p) =0
Sets the point of index index to the new point p. More...

Methods related to polygons

virtual Polygon_handle_struct add_polygon( Uint32 num_vertices, bool hole = false) =0
Adds a polygon to the mesh. More...
virtual Uint32 indices_size() const =0
Returns the total number of indices, i.e., the sum of the number of vertices of all polygons.
virtual bool  is_hole( Polygon_handle_struct p) const =0
Indicates whether the polygon p represents a hole.
virtual bool  is_polygon_size_constant() const =0
Indicates whether all polygons have the same number of vertices.
virtual Uint32 polygon_corners_size( Polygon_handle_struct p) const =0
Returns the number of vertices for a given polygon p. More...
virtual Uint32 polygons_size() const =0
Returns the number of polygons.

Methods related to the mesh connectivity

virtual const IPolygon_connectivity* access_mesh_connectivity() const =0
Returns the mesh connectivity. More...
virtual Sint32 attach_mesh_connectivity( IPolygon_connectivity* connectivity) =0
Attaches the mesh connectivity to the mesh. More...
virtual IPolygon_connectivity* edit_mesh_connectivity() =0
Detaches and returns the mesh connectivity. More...

Methods related to custom connectivities

virtual const IPolygon_connectivity* access_connectivity( Mesh_attribute_name name) const =0
Returns the connectivity for a given mesh attribute. More...
virtual Sint32 attach_connectivity( IPolygon_connectivity* connectivity) =0
Attaches a given connectivity to the mesh. More...
virtual IPolygon_connectivity* create_connectivity( Connectivity_map_type map_type = CONNECTIVITY_MAP_GENERIC) =0
Creates a new connectivity for non-per-primitive attributes. More...
virtual IPolygon_connectivity* edit_connectivity( Mesh_attribute_name name) =0
Detaches and returns the connectivity for a given mesh attribute. More...
virtual Sint32 remove_connectivity( Mesh_attribute_name name) =0
Removes the connectivity for a non-per-primitive mesh attribute. More...

Methods related to per-primitive attributes

virtual const IAttribute_vector* access_attribute_vector( Mesh_attribute_name name) const =0
Returns a per-primitive mesh attribute. More...
virtual Sint32 attach_attribute_vector( IAttribute_vector* attribute_vector) =0
Attaches a given per-primitive mesh attribute to the mesh. More...
virtual IAttribute_vector* create_attribute_vector( Mesh_attribute_name name, Uint32 dim = 1) =0
Creates a per-primitive mesh attribute. More...
virtual IAttribute_vector* edit_attribute_vector( Mesh_attribute_name name) =0
Detaches and returns a per-primitive mesh attribute. More...
virtual bool  has_attribute( Mesh_attribute_name name) const =0
Indicates whether the mesh has a particular mesh attribute (per-primitive or other types). More...
virtual Sint32 remove_attribute_vector( Mesh_attribute_name name) =0
Removes a per-primitive mesh attribute. More...

Methods related to the bounding box

virtual const Float32_3_struct& get_bbox_max() const =0
Returns the maximal corner of the bounding box.
virtual const Float32_3_struct& get_bbox_min() const =0
Returns the minimal corner of the bounding box.
virtual Bbox3_struct get_tight_bbox( const Float64_4_4_struct& transformation_matrix) const =0
Returns the bounding box of the polygon mesh after transformation. More...

Methods related to displacement

virtual Float32 get_maximum_displacement() const =0
Returns the maximum displacement of the polygon mesh. More...
virtual void set_maximum_displacement( Float32 displacement) =0
Sets the maximum displacement of the polygon mesh. More...

Member Functions

virtual const IAttribute_vector* mi::​neuraylib::​IPolygon_mesh::access_attribute_vector( Mesh_attribute_name name) const [pure virtual]

Returns a per-primitive mesh attribute.

Parameters

name
The name of the attribute, see Mesh_attribute_name. The attribute must be a per-primitive attribute.

Returns

The requested attribute vector, or NULL in case of failure.

virtual const IPolygon_connectivity* mi::​neuraylib::​IPolygon_mesh::access_connectivity( Mesh_attribute_name name) const [pure virtual]

Returns the connectivity for a given mesh attribute.

Parameters

name
The name of the attribute to return the connectivity for, see Mesh_attribute_name.

Returns

The connectivity for name , or NULL if there is no such attribute, or the attribute is a per-primitive attribute.

virtual const IPolygon_connectivity* mi::​neuraylib::​IPolygon_mesh::access_mesh_connectivity() const [pure virtual]

Returns the mesh connectivity.

Returns

The mesh connectivity, or NULL if it currently not attached.

virtual Polygon_handle_struct mi::​neuraylib::​IPolygon_mesh::add_polygon( Uint32 num_vertices, bool hole = false) [pure virtual]

Adds a polygon to the mesh. Afterwards all connectivities and attributes must be updated accordingly.

Parameters

num_vertices
The number of vertices of this polygon.
hole
Flag that identifies holes.

Returns

A handle for the new polygon, or a default-constructed handle if num_vertices < 3.

virtual Uint32 mi::​neuraylib::​IPolygon_mesh::append_point( const Float32_3_struct& p) [pure virtual]

Adds a point p to the end of all points and returns the index of the new point. The mesh class provides several overloaded versions for different parameter types. No information about the underlying storage is specified. The caller should use the best matching call for the caller's data representation.

virtual Uint32 mi::​neuraylib::​IPolygon_mesh::append_point( const Float64_3_struct& p) [pure virtual]

Adds a point p to the end of all points and returns the index of the new point. The mesh class provides several overloaded versions for different parameter types. No information about the underlying storage is specified. The caller should use the best matching call for the caller's data representation.

virtual Sint32 mi::​neuraylib::​IPolygon_mesh::attach_attribute_vector( IAttribute_vector* attribute_vector) [pure virtual]

Attaches a given per-primitive mesh attribute to the mesh. The attribute vector must not be used any longer after it has been attached.

See also:

create_attribute_vector(), edit_attribute_vector()

Returns

  • 0: Success.
  • -1: Invalid parameters (NULL pointer).
  • -2: The attribute vector has not been acquired from this mesh.
  • -3: The attribute vector is not a per-primitive attribute vector.
  • -4: The attribute vector is a per-primitive attribute vector and the number of elements does not match the number of polygons of the mesh.
  • -5: An attribute of the same name is already attached to the mesh (or to one of its connectivities).
virtual Sint32 mi::​neuraylib::​IPolygon_mesh::attach_connectivity( IPolygon_connectivity* connectivity) [pure virtual]

Attaches a given connectivity to the mesh. This implicitly binds all attributes of the connectivity to the mesh. The connectivity must not be used any longer after it has been attached.

See also:

create_connectivity(), edit_connectivity()

Returns

  • 0: Success.
  • -1: Invalid parameters (NULL pointer).
  • -2: The connectivity has not been created by or acquired from this mesh.
  • -3: The connectivity is already attached to the mesh.
  • -4: The connectivity is inconsistent (at least one index is too large for one of the attached attribute vectors).
virtual Sint32 mi::​neuraylib::​IPolygon_mesh::attach_mesh_connectivity( IPolygon_connectivity* connectivity) [pure virtual]

Attaches the mesh connectivity to the mesh. This implicitly binds all attributes of the connectivity to the mesh. The connectivity must not be used any longer after it has been attached.

See also:

edit_mesh_connectivity()

Returns

  • 0: Success.
  • -1: Invalid parameters (NULL pointer).
  • -2: The mesh connectivity has not been acquired from this mesh.
  • -3: The mesh connectivity of this mesh has already been attached.
  • -4: The mesh connectivity is inconsistent (at least one index is too large for the number of points or one of the attached attribute vectors).
  • -5: The connectivity is not a mesh connectivity.
virtual IAttribute_vector* mi::​neuraylib::​IPolygon_mesh::create_attribute_vector( Mesh_attribute_name name, Uint32 dim = 1) [pure virtual]

Creates a per-primitive mesh attribute. The attribute is not yet attached to the mesh. It needs to be attached before it is released.

See also:

attach_attribute_vector()

Parameters

name
The name of the attribute, see Mesh_attribute_name. The attribute must be a per-primitive attribute.
dim
Dimension of an attribute value. Only used for those attributes that have user specifiable dimensions.

Returns

The requested attribute vector, or NULL in case of failure.

virtual IPolygon_connectivity* mi::​neuraylib::​IPolygon_mesh::create_connectivity( Connectivity_map_type map_type = CONNECTIVITY_MAP_GENERIC) [pure virtual]

Creates a new connectivity for non-per-primitive attributes. The attribute is not yet attached to the mesh. It needs to be attached before it is released.

See also:

attach_connectivity()

virtual IAttribute_vector* mi::​neuraylib::​IPolygon_mesh::edit_attribute_vector( Mesh_attribute_name name) [pure virtual]

Detaches and returns a per-primitive mesh attribute. The attribute needs to be reattached before it is released. Otherwise, the attribute is effectively removed from the mesh.

See also:

attach_attribute_vector()

Parameters

name
The name of the attribute, see Mesh_attribute_name. The attribute must be a per-primitive attribute.

Returns

The requested attribute vector, or NULL in case of failure.

virtual IPolygon_connectivity* mi::​neuraylib::​IPolygon_mesh::edit_connectivity( Mesh_attribute_name name) [pure virtual]

Detaches and returns the connectivity for a given mesh attribute. The connectivity needs to be reattached before it is released.

See also:

attach_connectivity()

Parameters

name
The name of the attribute to return the connectivity for, see Mesh_attribute_name.

Returns

The connectivity for name , or NULL if there is no such attribute, or the attribute is a per-primitive attribute.

virtual IPolygon_connectivity* mi::​neuraylib::​IPolygon_mesh::edit_mesh_connectivity() [pure virtual]

Detaches and returns the mesh connectivity. The connectivity needs to be reattached before it is released.

See also:

attach_mesh_connectivity()

Returns

The mesh connectivity, or NULL if it currently not attached.

virtual const Float32_3_struct& mi::​neuraylib::​IPolygon_mesh::get_bbox_max() const [pure virtual]

Returns the maximal corner of the bounding box.

virtual const Float32_3_struct& mi::​neuraylib::​IPolygon_mesh::get_bbox_min() const [pure virtual]

Returns the minimal corner of the bounding box.

virtual Float32 mi::​neuraylib::​IPolygon_mesh::get_maximum_displacement() const [pure virtual]

Returns the maximum displacement of the polygon mesh.

See also:

set_maximum_displacement()

virtual Bbox3_struct mi::​neuraylib::​IPolygon_mesh::get_tight_bbox( const Float64_4_4_struct& transformation_matrix) const [pure virtual]

Returns the bounding box of the polygon mesh after transformation.

Parameters

transformation_matrix
The transformation matrix
virtual bool mi::​neuraylib::​IPolygon_mesh::has_attribute( Mesh_attribute_name name) const [pure virtual]

Indicates whether the mesh has a particular mesh attribute (per-primitive or other types).

Parameters

name
The name of the attribute to query, see Mesh_attribute_name.

Returns

true if the mesh has this attribute, false otherwise.

virtual Uint32 mi::​neuraylib::​IPolygon_mesh::indices_size() const [pure virtual]

Returns the total number of indices, i.e., the sum of the number of vertices of all polygons.

virtual bool mi::​neuraylib::​IPolygon_mesh::is_hole( Polygon_handle_struct p) const [pure virtual]

Indicates whether the polygon p represents a hole.

virtual bool mi::​neuraylib::​IPolygon_mesh::is_polygon_size_constant() const [pure virtual]

Indicates whether all polygons have the same number of vertices.

virtual Sint32 mi::​neuraylib::​IPolygon_mesh::point( Uint32 index, Float32_3_struct& p) const [pure virtual]

Returns the coordinates of the point of index index in the output parameter p. The mesh class provides several overloaded versions for different parameter types. No information about the underlying storage is specified. The caller should use the best matching call for the caller's data representation.

Returns

  • 0: Success.
  • -1: index is out of bounds.
virtual Sint32 mi::​neuraylib::​IPolygon_mesh::point( Uint32 index, Float64_3_struct& p) const [pure virtual]

Returns the coordinates of the point of index index in the output parameter p. The mesh class provides several overloaded versions for different parameter types. No information about the underlying storage is specified. The caller should use the best matching call for the caller's data representation.

Returns

  • 0: Success.
  • -1: index is out of bounds.
virtual Uint32 mi::​neuraylib::​IPolygon_mesh::points_capacity() const [pure virtual]

Returns the number of points for which space is allocated in the mesh. One can add points_capacity() - points_size() many points to the mesh before internal reallocation may become necessary.

See also:

reserve_points().

virtual Uint32 mi::​neuraylib::​IPolygon_mesh::points_size() const [pure virtual]

Returns the number of points in the mesh.

virtual Uint32 mi::​neuraylib::​IPolygon_mesh::polygon_corners_size( Polygon_handle_struct p) const [pure virtual]

Returns the number of vertices for a given polygon p.

Returns

The number of vertices, or 0 if p is out of bounds.

virtual Uint32 mi::​neuraylib::​IPolygon_mesh::polygons_size() const [pure virtual]

Returns the number of polygons.

virtual Sint32 mi::​neuraylib::​IPolygon_mesh::remove_attribute_vector( Mesh_attribute_name name) [pure virtual]

Removes a per-primitive mesh attribute.

Parameters

name
The name of the attribute, see Mesh_attribute_name. The attribute must be a per-primitive attribute.

Returns

  • 0: Success.
  • -1: There is no per-primitive attribute of the given name.
virtual Sint32 mi::​neuraylib::​IPolygon_mesh::remove_connectivity( Mesh_attribute_name name) [pure virtual]

Removes the connectivity for a non-per-primitive mesh attribute. If there are several mesh attributes attached to the same connectivity, only the given mesh attribute will be removed and the connectivity itself remains. Otherwise, removal of the connectivity implies removal of the corresponding mesh attribute.

Parameters

name
The name of the attribute to remove the connectivity for, see Mesh_attribute_name.

Returns

  • 0: Success.
  • -1: There is no connectivity for the given mesh attribute.
virtual void mi::​neuraylib::​IPolygon_mesh::reserve_points( Uint32 n) [pure virtual]

Reserves space for at least n points. Sets the internal capacity to at least n points before reallocation may become necessary. The number of points currently stored is not changed by this method.

See also:

points_capacity().

virtual void mi::​neuraylib::​IPolygon_mesh::set_maximum_displacement( Float32 displacement) [pure virtual]

Sets the maximum displacement of the polygon mesh. This value is the maximum absolute value of any displacement applied to the object (defaults to 0.0). The bounding box of the object will be expanded all around by this value.

virtual Sint32 mi::​neuraylib::​IPolygon_mesh::set_point( Uint32 index, const Float32_3_struct& p) [pure virtual]

Sets the point of index index to the new point p. The mesh class provides several overloaded versions for different parameter types. No information about the underlying storage is specified. The caller should use the best matching call for the caller's data representation.

Returns

  • 0: Success.
  • -1: index is out of bounds.
virtual Sint32 mi::​neuraylib::​IPolygon_mesh::set_point( Uint32 index, const Float64_3_struct& p) [pure virtual]

Sets the point of index index to the new point p. The mesh class provides several overloaded versions for different parameter types. No information about the underlying storage is specified. The caller should use the best matching call for the caller's data representation.

Returns

  • 0: Success.
  • -1: index is out of bounds.