Reference documentation for deal.II version GIT relicensing437g81ec864850 20240419 07:30:02+00:00

#include <deal.II/opencascade/manifold_lib.h>
Public Types  
using  FaceVertexNormals = std::array< Tensor< 1, spacedim >, GeometryInfo< dim >::vertices_per_face > 
Public Member Functions  
NormalToMeshProjectionManifold (const TopoDS_Shape &sh, const double tolerance=1e7)  
virtual std::unique_ptr< Manifold< dim, spacedim > >  clone () const override 
virtual Point< spacedim >  project_to_manifold (const ArrayView< const Point< spacedim > > &surrounding_points, const Point< spacedim > &candidate) const override 
virtual Point< spacedim >  get_new_point (const ArrayView< const Point< spacedim > > &surrounding_points, const ArrayView< const double > &weights) const override 
virtual void  get_new_points (const ArrayView< const Point< spacedim > > &surrounding_points, const Table< 2, double > &weights, ArrayView< Point< spacedim > > new_points) const override 
virtual Tensor< 1, spacedim >  get_tangent_vector (const Point< spacedim > &x1, const Point< spacedim > &x2) const override 
virtual Tensor< 1, spacedim >  normal_vector (const typename Triangulation< dim, spacedim >::face_iterator &face, const Point< spacedim > &p) const override 
virtual void  get_normals_at_vertices (const typename Triangulation< dim, spacedim >::face_iterator &face, typename Manifold< dim, spacedim >::FaceVertexNormals &face_vertex_normals) const override 
const Tensor< 1, spacedim > &  get_periodicity () const 
template<class Archive >  
void  serialize (Archive &ar, const unsigned int version) 
Computing normal vectors  
virtual void  get_normals_at_vertices (const typename Triangulation< dim, spacedim >::face_iterator &face, FaceVertexNormals &face_vertex_normals) const 
Computing the location of points.  
virtual Point< spacedim >  get_intermediate_point (const Point< spacedim > &p1, const Point< spacedim > &p2, const double w) const 
virtual Point< spacedim >  get_new_point_on_line (const typename Triangulation< dim, spacedim >::line_iterator &line) const 
virtual Point< spacedim >  get_new_point_on_quad (const typename Triangulation< dim, spacedim >::quad_iterator &quad) const 
virtual Point< spacedim >  get_new_point_on_hex (const typename Triangulation< dim, spacedim >::hex_iterator &hex) const 
Point< spacedim >  get_new_point_on_face (const typename Triangulation< dim, spacedim >::face_iterator &face) const 
Point< spacedim >  get_new_point_on_cell (const typename Triangulation< dim, spacedim >::cell_iterator &cell) const 
Subscriptor functionality  
Classes derived from Subscriptor provide a facility to subscribe to this object. This is mostly used by the SmartPointer class.  
void  subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const 
void  unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const 
unsigned int  n_subscriptions () const 
template<typename StreamType >  
void  list_subscribers (StreamType &stream) const 
void  list_subscribers () const 
Static Public Member Functions  
static ::ExceptionBase &  ExcInUse (int arg1, std::string arg2, std::string arg3) 
static ::ExceptionBase &  ExcNoSubscriber (std::string arg1, std::string arg2) 
Protected Attributes  
const TopoDS_Shape  sh 
const double  tolerance 
Private Types  
using  map_value_type = decltype(counter_map)::value_type 
using  map_iterator = decltype(counter_map)::iterator 
Private Member Functions  
void  check_no_subscribers () const noexcept 
Static Private Member Functions  
static ::ExceptionBase &  ExcPeriodicBox (int arg1, Point< spacedim > arg2, double arg3) 
Private Attributes  
const Tensor< 1, spacedim >  periodicity 
std::atomic< unsigned int >  counter 
std::map< std::string, unsigned int >  counter_map 
std::vector< std::atomic< bool > * >  validity_pointers 
const std::type_info *  object_info 
Static Private Attributes  
static std::mutex  mutex 
A Manifold object based on OpenCASCADE TopoDS_Shape where new points are first computed by averaging the surrounding points in the same way as FlatManifold does, and then projecting them using OpenCASCADE utilities onto the manifold along a direction which is an estimation of the surrounding points (hence mesh cell) normal.
The direction normal to the mesh is particularly useful because it is the direction in which the mesh is missing nodes. For instance, during the refinement of a cell a new node is initially created around the baricenter of the cell. This location somehow ensures a uniform distance from the nodes of the old cell. Projecting such cell baricenter onto the CAD surface in the direction normal to the original cell will then retain uniform distance from the points of the original cell. Of course, at the stage of mesh generation, no dof handler nor finite element are defined, and such direction has to be estimated. For the case in which 8 surrounding points are present, 4 different triangles are identified with the points assigned, and the normals of such triangles are averaged to obtain the approximation of the normal to the cell.
The case in which 2 surrounding points are present (i.e.:a cell edge is being refined) is of course more tricky. The average of the CAD surface normals at the 2 surrounding points is first computed, and then projected onto the plane normal to the segment linking the surrounding points. This again is an attempt to have the new point with equal distance with respect to the surrounding points
This class only operates with CAD faces and makes the assumption that the shape you pass to it contains at least one face. If that is not the case, an Exception is thrown. In debug mode there is a sanity check to make sure that the surrounding points (the ones used in project_to_manifold()) actually live on the Manifold, i.e., calling OpenCASCADE::closest_point() on those points leaves them untouched. If this is not the case, an ExcPointNotOnManifold is thrown.
Notice that this type of Manifold descriptor may fail to give results if the triangulation to be refined is close to the boundary of the given TopoDS_Shape, or when the normal direction estimated from the surrounding points does not intersect the shape. An exception is thrown when this happens.
Definition at line 229 of file manifold_lib.h.

inherited 
Type keeping information about the normals at the vertices of a face of a cell. Thus, there are GeometryInfo<dim>::vertices_per_face
normal vectors, that define the tangent spaces of the boundary at the vertices. Note that the vectors stored in this object are not required to be normalized, nor to actually point outward, as one often will only want to check for orthogonality to define the tangent plane; if a function requires the normals to be normalized, then it must do so itself.
For obvious reasons, this type is not useful in 1d.
Definition at line 305 of file manifold.h.

privateinherited 
The data type used in counter_map.
Definition at line 229 of file subscriptor.h.

privateinherited 
The iterator type used in counter_map.
Definition at line 234 of file subscriptor.h.
OpenCASCADE::NormalToMeshProjectionManifold< dim, spacedim >::NormalToMeshProjectionManifold  (  const TopoDS_Shape &  sh, 
const double  tolerance = 1e7 

) 
Construct a Manifold object which will project points on the TopoDS_Shape sh
, along a direction which is approximately normal to the mesh cell.
Definition at line 191 of file manifold_lib.cc.

overridevirtual 
Clone the current Manifold.
Reimplemented from FlatManifold< dim, spacedim >.
Definition at line 206 of file manifold_lib.cc.

overridevirtual 
Perform the actual projection onto the manifold. This function, in debug mode, checks that each of the surrounding_points
is within tolerance from the given TopoDS_Shape. If this is not the case, an exception is thrown.
Reimplemented from FlatManifold< dim, spacedim >.
Definition at line 394 of file manifold_lib.cc.

overridevirtualinherited 
Let the new point be the average sum of surrounding vertices.
This particular implementation constructs the weighted average of the surrounding points, and then calls internally the function project_to_manifold(). The reason why we do it this way, is to allow lazy programmers to implement only the project_to_manifold() function for their own Manifold classes which are small (or trivial) perturbations of a flat manifold. This is the case whenever the coarse mesh is a decent approximation of the manifold geometry. In this case, the middle point of a cell is close to true middle point of the manifold, and a projection may suffice.
For most simple geometries, it is possible to get reasonable results by deriving your own Manifold class from FlatManifold, and write a new interface only for the project_to_manifold function. You will have good approximations also with large deformations, as long as in the coarsest mesh size you are trying to refine, the middle point is not too far from the manifold mid point, i.e., as long as the coarse mesh size is small enough.
Reimplemented from Manifold< dim, spacedim >.

overridevirtualinherited 
Compute a new set of points that interpolate between the given points surrounding_points
. weights
is a table with as many columns as surrounding_points.size()
. The number of rows in weights
must match the length of new_points
.
For this particular implementation, the interpolation of the surrounding_points
according to the weights
is simply performed in Cartesian space.
Reimplemented from Manifold< dim, spacedim >.

overridevirtualinherited 
Return a vector that, at \(\mathbf x_1\), is tangential to the geodesic that connects two points \(\mathbf x_1,\mathbf x_2\). For the current class, we assume that the manifold is flat, so the geodesic is the straight line between the two points, and we return \(\mathbf x_2\mathbf x_1\). The normalization of the vector is chosen so that it fits the convention described in Manifold::get_tangent_vector().
x1  The first point that describes the geodesic, and the one at which the "direction" is to be evaluated. 
x2  The second point that describes the geodesic. 
Reimplemented from Manifold< dim, spacedim >.

overridevirtualinherited 
Return the normal vector to the given face at point p taking into account that quadrilateral faces of hexahedral cells in 3d may not be planar. In those cases, the face is assumed to have a geometry described by a bilinear function, and the normal vector is computed by embedding this bilinear form into a Cartesian space with a flat metric.
Reimplemented from Manifold< dim, spacedim >.

overridevirtualinherited 
Compute the normal vectors to the boundary at each vertex of the given face taking into account that quadrilateral faces of hexahedral cells in 3d may not be planar. In those cases, the face is assumed to have a geometry described by a bilinear function, and the normal vector is computed by embedding this bilinear form into a Cartesian space with a flat metric.

virtualinherited 
Compute the normal vectors to the boundary at each vertex of the given face embedded in the Manifold. It is not required that the normal vectors be normed somehow. Neither is it required that the normals actually point outward.
This function is needed to compute data for C1 mappings. The default implementation calls normal_vector() on each vertex.
Note that when computing normal vectors at a vertex where the boundary is not differentiable, you have to make sure that you compute the onesided limits, i.e. limit with respect to points inside the given face.

inherited 
Return the periodicity of this Manifold.

staticprivateinherited 

virtualinherited 
Return an intermediate point between two given points. Overloading this function allows the default pairwise reduction implementation of the method get_new_point() that takes a Quadrature object as input to work properly.
An implementation of this function should returns a parametric curve on the manifold, joining the points p1
and p2
, with parameter w
in the interval [0,1]. In particular get_intermediate_point(p1, p2, 0.0)
should return p1
and get_intermediate_point(p1, p2, 1.0)
should return p2
.
In its default implementation, this function calls the project_to_manifold() method with the convex combination of p1
and p2
. User classes can get away by simply implementing the project_to_manifold() method.
Reimplemented in ChartManifold< dim, 3, 3 >, ChartManifold< dim, dim, 3 >, ChartManifold< dim, dim, dim >, ChartManifold< dim, spacedim, 1 >, ChartManifold< dim, spacedim, 2 >, ChartManifold< dim, spacedim_A+spacedim_B, chartdim_A+chartdim_B >, ChartManifold< dim_A, spacedim_A, chartdim_A >, and ChartManifold< dim_B, spacedim_B, chartdim_B >.

virtualinherited 
Backward compatibility interface. Return the point which shall become the new middle vertex of the two children of a regular line. In 2d, this line is a line at the boundary, while in 3d, it is bounding a face at the boundary (the lines therefore is also on the boundary).
The default implementation of this function passes its argument to the Manifolds::get_default_points_and_weights() function, and then calls the Manifold<dim,spacedim>::get_new_point() function. User derived classes can overload Manifold<dim,spacedim>::get_new_point() or Manifold<dim,spacedim>::project_to_manifold(), which is called by the default implementation of Manifold<dim,spacedim>::get_new_point().

virtualinherited 
Backward compatibility interface. Return the point which shall become the common point of the four children of a quad at the boundary in three or more spatial dimensions. This function therefore is only useful in at least three dimensions and should not be called for lower dimensions.
This function is called after the four lines bounding the given quad
are refined, so you may want to use the information provided by quad>line(i)>child(j)
, i=0...3
, j=0,1
.
The default implementation of this function passes its argument to the Manifolds::get_default_points_and_weights() function, and then calls the Manifold<dim,spacedim>::get_new_point() function. User derived classes can overload Manifold<dim,spacedim>::get_new_point() or Manifold<dim,spacedim>::project_to_manifold(), which is called by the default implementation of Manifold<dim,spacedim>::get_new_point().

virtualinherited 
Backward compatibility interface. Return the point which shall become the common point of the eight children of a hex in three or spatial dimensions. This function therefore is only useful in at least three dimensions and should not be called for lower dimensions.
This function is called after the all the bounding objects of the given hex
are refined, so you may want to use the information provided by hex>quad(i)>line(j)>child(k)
, i=0...5
, j=0...3
, k=0,1
.
The default implementation of this function passes its argument to the Manifolds::get_default_points_and_weights() function, and then calls the Manifold<dim,spacedim>::get_new_point() function. User derived classes can overload Manifold<dim,spacedim>::get_new_point() or Manifold<dim,spacedim>::project_to_manifold(), which is called by the default implementation of Manifold<dim,spacedim>::get_new_point().

inherited 
Backward compatibility interface. Depending on dim=2
or dim=3
this function calls the get_new_point_on_line or the get_new_point_on_quad function. It throws an exception for dim=1
. This wrapper allows dimension independent programming.

inherited 
Backward compatibility interface. Depending on dim=1
, dim=2
or dim=3
this function calls the get_new_point_on_line, get_new_point_on_quad or the get_new_point_on_hex function. This wrapper allows dimension independent programming.

inherited 
Subscribes a user of the object by storing the pointer validity
. The subscriber may be identified by text supplied as identifier
.
Definition at line 135 of file subscriptor.cc.

inherited 
Unsubscribes a user from the object.
identifier
and the validity
pointer must be the same as the one supplied to subscribe(). Definition at line 155 of file subscriptor.cc.

inlineinherited 
Return the present number of subscriptions to this object. This allows to use this class for reference counted lifetime determination where the last one to unsubscribe also deletes the object.
Definition at line 300 of file subscriptor.h.

inlineinherited 
List the subscribers to the input stream
.
Definition at line 317 of file subscriptor.h.

inherited 
List the subscribers to deallog
.
Definition at line 203 of file subscriptor.cc.

inlineinherited 
Read or write the data of this object to or from a stream for the purpose of serialization using the BOOST serialization library.
This function does not actually serialize any of the member variables of this class. The reason is that what this class stores is only who subscribes to this object, but who does so at the time of storing the contents of this object does not necessarily have anything to do with who subscribes to the object when it is restored. Consequently, we do not want to overwrite the subscribers at the time of restoring, and then there is no reason to write the subscribers out in the first place.
Definition at line 309 of file subscriptor.h.

privatenoexceptinherited 
Check that there are no objects subscribing to this object. If this check passes then it is safe to destroy the current object. It this check fails then this function will either abort or print an error message to deallog (by using the AssertNothrow mechanism), but will not throw an exception.
Definition at line 52 of file subscriptor.cc.

protected 
The topological shape which is used internally to project points. You can construct such a shape by calling the OpenCASCADE::read_IGES() function, which will create a TopoDS_Shape with the geometry contained in the IGES file.
Definition at line 264 of file manifold_lib.h.

protected 
Relative tolerance used by this class to compute distances.
Definition at line 269 of file manifold_lib.h.

privateinherited 
The periodicity of this Manifold. Periodicity affects the way a middle point is computed. It is assumed that if two points are more than half period distant, then the distance should be computed by crossing the periodicity boundary, i.e., the average is computed by adding a full period to the sum of the two. For example, if along direction 0 we have 2*pi periodicity, then the average of (2*pieps) and (eps) is not pi, but 2*pi (or zero), since, on a periodic manifold, these two points are at distance 2*eps and not (2*pieps).
A periodicity 0 along one direction means no periodicity. This is the default value for all directions.
Definition at line 796 of file manifold.h.

mutableprivateinherited 
Store the number of objects which subscribed to this object. Initially, this number is zero, and upon destruction it shall be zero again (i.e. all objects which subscribed should have unsubscribed again).
The creator (and owner) of an object is counted in the map below if HE manages to supply identification.
We use the mutable
keyword in order to allow subscription to constant objects also.
This counter may be read from and written to concurrently in multithreaded code: hence we use the std::atomic
class template.
Definition at line 218 of file subscriptor.h.

mutableprivateinherited 
In this map, we count subscriptions for each different identification string supplied to subscribe().
Definition at line 224 of file subscriptor.h.

mutableprivateinherited 
In this vector, we store pointers to the validity bool in the SmartPointer objects that subscribe to this class.
Definition at line 240 of file subscriptor.h.

mutableprivateinherited 
Pointer to the typeinfo object of this object, from which we can later deduce the class name. Since this information on the derived class is neither available in the destructor, nor in the constructor, we obtain it in between and store it here.
Definition at line 248 of file subscriptor.h.

staticprivateinherited 
A mutex used to ensure data consistency when accessing the mutable
members of this class. This lock is used in the subscribe() and unsubscribe() functions, as well as in list_subscribers()
.
Definition at line 271 of file subscriptor.h.