Interface representing a polygon mesh. More...

Inheritance diagram for mi::IPolygon_mesh:

[legend]

Public Member Functions
Methods related to points
virtual Uint32	points_size () const =0
	Returns the number of points in the mesh. More...

virtual Uint32	points_capacity () const =0
	Returns the number of points for which space is allocated in the mesh. More...

virtual void	reserve_points (Uint32 n)=0
	Reserves space for at least `n` points. 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	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	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 Uint32	polygons_size () const =0
	Returns the number of polygons. More...

virtual Uint32	polygon_corners_size (Polygon_handle_struct p) const =0
	Returns the number of vertices for a given polygon `p`. More...

virtual bool	is_hole (Polygon_handle_struct p) const =0
	Indicates whether the polygon `p` represents a hole. 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. More...

virtual bool	is_polygon_size_constant () const =0
	Indicates whether all polygons have the same number of vertices. More...

virtual Polygon_handle_struct	add_polygon (Uint32 num_vertices, bool hole=false)=0
	Adds a polygon to the mesh. More...

Methods related to the mesh connectivity
virtual const IPolygon_connectivity *	access_mesh_connectivity () const =0
	Returns the mesh connectivity. More...

virtual IPolygon_connectivity *	edit_mesh_connectivity ()=0
	Detaches and returns the mesh connectivity. More...

virtual Sint32	attach_mesh_connectivity (IPolygon_connectivity *connectivity)=0
	Attaches the mesh connectivity to the mesh. More...

Methods related to custom connectivities
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 const IPolygon_connectivity *	access_connectivity (Mesh_attribute_name name) const =0
	Returns the connectivity for a given mesh attribute. More...

virtual IPolygon_connectivity *	edit_connectivity (Mesh_attribute_name name)=0
	Detaches and 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...

Methods related to per-primitive attributes
virtual bool	has_attribute (Mesh_attribute_name name) const =0
	Indicates whether the mesh has a particular mesh attribute. More...

virtual IAttribute_vector *	create_attribute_vector (Mesh_attribute_name name, Uint32 dim=1)=0
	Creates a per-primitive mesh attribute. More...

virtual const IAttribute_vector *	access_attribute_vector (Mesh_attribute_name name) const =0
	Returns 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 Sint32	attach_attribute_vector (IAttribute_vector *attribute_vector)=0
	Attaches a given per-primitive mesh attribute to the mesh. More...

Methods related to the bounding box
virtual const Float32_3_struct &	get_bbox_min () const =0
	Returns the minimal corner of the bounding box. More...

virtual const Float32_3_struct &	get_bbox_max () const =0
	Returns the maximal corner of the bounding box. More...

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

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

Additional Inherited Members
Public Types inherited from mi::base::Interface_declare< 0x598d264b, 0x1d1f, 0x40c9, 0x88, 0xe6, 0x54, 0x19, 0x30, 0x08, 0xc7, 0xb2, IScene_element >
typedef Interface_declare< id1, id2, id3, id4, id5, id6, id7, id8, id9, id10, id11, IScene_element >	Self
	Own type. More...

typedef Uuid_t< id1, id2, id3, id4, id5, id6, id7, id8, id9, id10, id11 >	IID
	Declares the interface ID (IID) of this interface. More...

Static Public Member Functions inherited from mi::base::Interface_declare< 0x598d264b, 0x1d1f, 0x40c9, 0x88, 0xe6, 0x54, 0x19, 0x30, 0x08, 0xc7, 0xb2, IScene_element >
static bool	compare_iid (const Uuid &iid)
	Compares the interface ID `iid` against the interface ID of this interface and of its ancestors. More...

Detailed 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::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::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::Mesh_attribute_name and mi::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::IAttribute_set for information how to control the tessellation of the polygon mesh.

See Also: mi::IPolygon_connectivity; mi::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::IPolygon_mesh> mesh(
    transaction->create<mi::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::Polygon_handle polygon_handle( mesh->add_polygon( 4));

mi::base::Handle<mi::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::IAttribute_vector> texture_coordinates(
    mesh_connectivity->create_attribute_vector( mi::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::IPolygon_connectivity> normal_connectivity(
    mesh->create_connectivity( mi::CONNECTIVITY_MAP_GENERIC));
normal_connectivity->set_polygon_indices( polygon_handle, 0, 0, 0, 0);
// Create an attribute vector for normals

mi::base::Handle<mi::IAttribute_vector> normals(
    normal_connectivity->create_attribute_vector( mi::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());

Member Function Documentation

virtual const IAttribute_vector* mi::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::IPolygon_mesh::access_connectivity ( Mesh_attribute_name name) const

pure virtual

Returns the connectivity for a given mesh attribute.

Parameters

name	The attribute to return the connectivity for.

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::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::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::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::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::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::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::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::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::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::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::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 attribute to return the connectivity for.

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::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::IPolygon_mesh::get_bbox_max ( ) const

pure virtual

Returns the maximal corner of the bounding box.

virtual const Float32_3_struct& mi::IPolygon_mesh::get_bbox_min ( ) const

pure virtual

Returns the minimal corner of the bounding box.

virtual Float32 mi::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::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::IPolygon_mesh::has_attribute ( Mesh_attribute_name name) const

pure virtual

Indicates whether the mesh has a particular mesh attribute.

Parameters

name	The attribute to query.

Returns: true if the mesh has this attribute, false otherwise.

virtual Uint32 mi::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::IPolygon_mesh::is_hole ( Polygon_handle_struct p) const

pure virtual

Indicates whether the polygon p represents a hole.

virtual bool mi::IPolygon_mesh::is_polygon_size_constant ( ) const

pure virtual

Indicates whether all polygons have the same number of vertices.

virtual Sint32 mi::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::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::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::IPolygon_mesh::points_size ( ) const

pure virtual

Returns the number of points in the mesh.

virtual Uint32 mi::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::IPolygon_mesh::polygons_size ( ) const

pure virtual

Returns the number of polygons.

virtual void mi::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::IPolygon_mesh::set_maximum_displacement ( Float32 displacement)

pure virtual

Sets the maximum displacement of the polygon mesh.

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

virtual Sint32 mi::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::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.

Public Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation