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vtkSimpleCellTessellator Class Reference

helper class to perform cell tessellation More...

#include <vtkSimpleCellTessellator.h>

Inherits vtkGenericCellTessellator.

Collaboration diagram for vtkSimpleCellTessellator:
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Public Types

typedef vtkGenericCellTessellator Superclass
 

Public Member Functions

virtual const char * GetClassName ()
 
virtual int IsA (const char *type)
 
void PrintSelf (ostream &os, vtkIndent indent)
 
void Reset ()
 
void Initialize (vtkGenericDataSet *ds)
 
int GetFixedSubdivisions ()
 
int GetMaxSubdivisionLevel ()
 
int GetMaxAdaptiveSubdivisions ()
 
void SetFixedSubdivisions (int level)
 
void SetMaxSubdivisionLevel (int level)
 
virtual vtkGenericAdaptorCell * GetGenericCell ()
 
void TessellateFace (vtkGenericAdaptorCell *cell, vtkGenericAttributeCollection *att, vtkIdType index, vtkDoubleArray *points, vtkCellArray *cellArray, vtkPointData *internalPd)
 
void Tessellate (vtkGenericAdaptorCell *cell, vtkGenericAttributeCollection *att, vtkDoubleArray *points, vtkCellArray *cellArray, vtkPointData *internalPd)
 
void Triangulate (vtkGenericAdaptorCell *cell, vtkGenericAttributeCollection *att, vtkDoubleArray *points, vtkCellArray *cellArray, vtkPointData *internalPd)
 
void SetSubdivisionLevels (int fixed, int maxLevel)
 

Static Public Member Functions

static vtkSimpleCellTessellatorNew ()
 
static int IsTypeOf (const char *type)
 
static vtkSimpleCellTessellatorSafeDownCast (vtkObject *o)
 

Protected Member Functions

 vtkSimpleCellTessellator ()
 
 ~vtkSimpleCellTessellator ()
 
void CopyPoint (vtkIdType pointId)
 
void InsertEdgesIntoEdgeTable (vtkTriangleTile &tri)
 
void RemoveEdgesFromEdgeTable (vtkTriangleTile &tri)
 
void InsertPointsIntoEdgeTable (vtkTriangleTile &tri)
 
void InsertEdgesIntoEdgeTable (vtkTetraTile &tetra)
 
void RemoveEdgesFromEdgeTable (vtkTetraTile &tetra)
 
void AllocateScalars (int size)
 
int FindEdgeReferenceCount (double p1[3], double p2[3], vtkIdType &e1, vtkIdType &e2)
 
int GetNumberOfCellsUsingFace (int faceId)
 
int GetNumberOfCellsUsingEdge (int edgeId)
 
int IsEdgeOnFace (double p1[3], double p2[3])
 
int FindEdgeParent2D (double p1[3], double p2[3], int &localId)
 
int FindEdgeParent (double p1[3], double p2[3], int &localId)
 
void AllocatePointIds (int size)
 
void InitTetraTile (vtkTetraTile &root, vtkIdType *localIds, vtkIdType *ids, int *edgeIds, int *faceIds)
 
void TriangulateTriangle (vtkGenericAdaptorCell *cell, vtkIdType *localIds, vtkIdType *ids, int *edgeIds, vtkGenericAttributeCollection *att, vtkDoubleArray *points, vtkCellArray *cellArray, vtkPointData *internalPd)
 
int FacesAreEqual (int *originalFace, int face[3])
 

Protected Attributes

vtkGenericEdgeTableEdgeTable
 
vtkGenericAdaptorCell * GenericCell
 
double * Scalars
 
int ScalarsCapacity
 
int PointOffset
 
vtkGenericCellIterator * CellIterator
 
vtkGenericAttributeCollection * AttributeCollection
 
vtkGenericDataSet * DataSet
 
vtkIdType NumberOfPoints
 
int FixedSubdivisions
 
int MaxSubdivisionLevel
 
int CurrentSubdivisionLevel
 
vtkOrderedTriangulatorTriangulator
 
vtkCellArrayConnectivity
 
vtkPolygonPolygon
 
vtkIdListTriangleIds
 
vtkIdTypePointIds
 
int PointIdsCapacity
 
vtkDoubleArrayTessellatePoints
 
vtkCellArrayTessellateCellArray
 
vtkPointDataTessellatePointData
 
int * EdgeIds
 
int * FaceIds
 

Friends

class vtkTetraTile
 
class vtkTriangleTile
 

Detailed Description

helper class to perform cell tessellation

vtkSimpleCellTessellator is a helper class to perform adaptive tessellation of particular cell topologies. The major purpose for this class is to transform higher-order cell types (e.g., higher-order finite elements) into linear cells that can then be easily visualized by VTK. This class works in conjunction with the vtkGenericDataSet and vtkGenericAdaptorCell classes.

This algorithm is based on edge subdivision. An error metric along each edge is evaluated, and if the error is greater than some tolerance, the edge is subdivided (as well as all connected 2D and 3D cells). The process repeats until the error metric is satisfied. Since the algorithm is based on edge subdivision it inherently avoid T-junctions.

A significant issue addressed by this algorithm is to insure face compatibility across neigboring cells. That is, diagonals due to face triangulation must match to insure that the mesh is compatible. The algorithm employs a precomputed table to accelerate the tessellation process. The table was generated with the help of vtkOrderedTriangulator the basic idea is that the choice of diagonal is made only by considering the relative value of the point ids.

See Also
vtkGenericCellTessellator vtkGenericSubdivisionErrorMetric vtkAttributesErrorMetric vtkGeometricErrorMetric vtkViewDependentErrorMetric
Tests:
vtkSimpleCellTessellator (Tests)

Definition at line 69 of file vtkSimpleCellTessellator.h.

Member Typedef Documentation

typedef vtkGenericCellTessellator vtkSimpleCellTessellator::Superclass

Definition at line 73 of file vtkSimpleCellTessellator.h.

Constructor & Destructor Documentation

vtkSimpleCellTessellator::vtkSimpleCellTessellator ( )
protected
vtkSimpleCellTessellator::~vtkSimpleCellTessellator ( )
protected

Member Function Documentation

static vtkSimpleCellTessellator* vtkSimpleCellTessellator::New ( )
static
virtual const char* vtkSimpleCellTessellator::GetClassName ( )
virtual
static int vtkSimpleCellTessellator::IsTypeOf ( const char *  type)
static
virtual int vtkSimpleCellTessellator::IsA ( const char *  type)
virtual
static vtkSimpleCellTessellator* vtkSimpleCellTessellator::SafeDownCast ( vtkObject o)
static
void vtkSimpleCellTessellator::PrintSelf ( ostream &  os,
vtkIndent  indent 
)
virtual vtkGenericAdaptorCell* vtkSimpleCellTessellator::GetGenericCell ( )
virtual

Get the higher order cell in order to access the evaluation function.

void vtkSimpleCellTessellator::TessellateFace ( vtkGenericAdaptorCell *  cell,
vtkGenericAttributeCollection *  att,
vtkIdType  index,
vtkDoubleArray points,
vtkCellArray cellArray,
vtkPointData internalPd 
)

Tessellate a face of a 3D `cell'. The face is specified by the index value. The result is a set of smaller linear triangles in `cellArray' with `points' and point data `internalPd'.

Precondition
cell_exists: cell!=0
valid_dimension: cell->GetDimension()==3
valid_index_range: (index>=0) && (index<cell->GetNumberOfBoundaries(2))
att_exists: att!=0
points_exists: points!=0
cellArray_exists: cellArray!=0
internalPd_exists: internalPd!=0
void vtkSimpleCellTessellator::Tessellate ( vtkGenericAdaptorCell *  cell,
vtkGenericAttributeCollection *  att,
vtkDoubleArray points,
vtkCellArray cellArray,
vtkPointData internalPd 
)

Tessellate a 3D `cell'. The result is a set of smaller linear tetrahedra in `cellArray' with `points' and point data `internalPd'.

Precondition
cell_exists: cell!=0
valid_dimension: cell->GetDimension()==3
att_exists: att!=0
points_exists: points!=0
cellArray_exists: cellArray!=0
internalPd_exists: internalPd!=0
void vtkSimpleCellTessellator::Triangulate ( vtkGenericAdaptorCell *  cell,
vtkGenericAttributeCollection *  att,
vtkDoubleArray points,
vtkCellArray cellArray,
vtkPointData internalPd 
)

Triangulate a 2D `cell'. The result is a set of smaller linear triangles in `cellArray' with `points' and point data `internalPd'.

Precondition
cell_exists: cell!=0
valid_dimension: cell->GetDimension()==2
att_exists: att!=0
points_exists: points!=0
cellArray_exists: cellArray!=0
internalPd_exists: internalPd!=0
void vtkSimpleCellTessellator::Reset ( )

Reset the output for repeated use of this class.

void vtkSimpleCellTessellator::Initialize ( vtkGenericDataSet *  ds)

Initialize the tessellator with a data set `ds'.

int vtkSimpleCellTessellator::GetFixedSubdivisions ( )

Return the number of fixed subdivisions. It is used to prevent from infinite loop in degenerated cases. For order 3 or higher, if the inflection point is exactly on the mid-point, error metric will not detect that a subdivision is required. 0 means no fixed subdivision: there will be only adaptive subdivisions. The algorithm first performs `GetFixedSubdivisions' non adaptive subdivisions followed by at most `GetMaxAdaptiveSubdivisions' adaptive subdivisions. Hence, there are at most `GetMaxSubdivisionLevel' subdivisions.

Postcondition
positive_result: result>=0 && result<=GetMaxSubdivisionLevel()
int vtkSimpleCellTessellator::GetMaxSubdivisionLevel ( )

Return the maximum level of subdivision. It is used to prevent from infinite loop in degenerated cases. For order 3 or higher, if the inflection point is exactly on the mid-point, error metric will not detect that a subdivision is required. 0 means no subdivision, neither fixed nor adaptive.

Postcondition
positive_result: result>=GetFixedSubdivisions()
int vtkSimpleCellTessellator::GetMaxAdaptiveSubdivisions ( )

Return the maximum number of adaptive subdivisions.

Postcondition
valid_result: result==GetMaxSubdivisionLevel()-GetFixedSubdivisions()
void vtkSimpleCellTessellator::SetFixedSubdivisions ( int  level)

Set the number of fixed subdivisions. See GetFixedSubdivisions() for more explanations.

Precondition
positive_level: level>=0 && level<=GetMaxSubdivisionLevel()
Postcondition
is_set: GetFixedSubdivisions()==level
void vtkSimpleCellTessellator::SetMaxSubdivisionLevel ( int  level)

Set the maximum level of subdivision. See GetMaxSubdivisionLevel() for more explanations.

Precondition
positive_level: level>=GetFixedSubdivisions()
Postcondition
is_set: level==GetMaxSubdivisionLevel()
void vtkSimpleCellTessellator::SetSubdivisionLevels ( int  fixed,
int  maxLevel 
)

Set both the number of fixed subdivisions and the maximum level of subdivisions. See GetFixedSubdivisions(), GetMaxSubdivisionLevel() and GetMaxAdaptiveSubdivisions() for more explanations.

Precondition
positive_fixed: fixed>=0
valid_range: fixed<=maxLevel
Postcondition
fixed_is_set: fixed==GetFixedSubdivisions()
maxLevel_is_set: maxLevel==GetMaxSubdivisionLevel()
void vtkSimpleCellTessellator::CopyPoint ( vtkIdType  pointId)
protected

Extract point `pointId' from the edge table to the output point and output point data.

void vtkSimpleCellTessellator::InsertEdgesIntoEdgeTable ( vtkTriangleTile tri)
protected
void vtkSimpleCellTessellator::RemoveEdgesFromEdgeTable ( vtkTriangleTile tri)
protected
void vtkSimpleCellTessellator::InsertPointsIntoEdgeTable ( vtkTriangleTile tri)
protected
void vtkSimpleCellTessellator::InsertEdgesIntoEdgeTable ( vtkTetraTile tetra)
protected
void vtkSimpleCellTessellator::RemoveEdgesFromEdgeTable ( vtkTetraTile tetra)
protected
void vtkSimpleCellTessellator::InitTetraTile ( vtkTetraTile root,
vtkIdType localIds,
vtkIdType ids,
int *  edgeIds,
int *  faceIds 
)
protected

Initialize `root' with the sub-tetra defined by the `localIds' points on the complex cell, `ids' are the global ids over the mesh of those points. The sub-tetra is also defined by the ids of its edges and of its faces relative to the complex cell. -1 means that the edge or the face of the sub-tetra is not an original edge or face of the complex cell.

Precondition
cell_exists: this->GenericCell!=0
localIds_exists: localIds!=0
localIds_size: sizeof(localIds)==4
ids_exists: ids!=0
ids_size: sizeof(ids)==4
edgeIds_exists: edgeIds!=0
edgeIds_size: sizeof(edgeIds)==6
faceIds_exists: faceIds!=0
faceIds_size: sizeof(faceIds)==4
void vtkSimpleCellTessellator::TriangulateTriangle ( vtkGenericAdaptorCell *  cell,
vtkIdType localIds,
vtkIdType ids,
int *  edgeIds,
vtkGenericAttributeCollection *  att,
vtkDoubleArray points,
vtkCellArray cellArray,
vtkPointData internalPd 
)
protected

Triangulate a triangle of `cell'. This triangle can be the top-level triangle if the cell is a triangle or a toplevel sub-triangle is the cell is a polygon, or a triangular face of a 3D cell or a top-level sub-triangle of a face of a 3D cell if the face is not a triangle. Arguments `localIds', `ids' and `edgeIds' have the same meaning than for InitTetraTile.

Precondition
cell_exists: cell!=0
localIds_exists: localIds!=0
localIds_size: sizeof(localIds)==3
ids_exists: ids!=0
ids_size: sizeof(ids)==3
edgeIds_exists: edgeIds!=0
edgeIds_size: sizeof(edgeIds)==3
void vtkSimpleCellTessellator::AllocateScalars ( int  size)
protected

Allocate some memory if Scalars does not exists or is smaller than size.

Precondition
positive_size: size>0
int vtkSimpleCellTessellator::FindEdgeReferenceCount ( double  p1[3],
double  p2[3],
vtkIdType e1,
vtkIdType e2 
)
protected
int vtkSimpleCellTessellator::GetNumberOfCellsUsingFace ( int  faceId)
protected
int vtkSimpleCellTessellator::GetNumberOfCellsUsingEdge ( int  edgeId)
protected
int vtkSimpleCellTessellator::IsEdgeOnFace ( double  p1[3],
double  p2[3] 
)
protected

Is the edge defined by vertices (`p1',`p2') in parametric coordinates on some edge of the original tetrahedron? If yes return on which edge it is, else return -1.

Precondition
p1!=p2
p1 and p2 are in bounding box (0,0,0) (1,1,1)
Postcondition
valid_result: (result==-1) || ( result>=0 && result<=5 )
int vtkSimpleCellTessellator::FindEdgeParent2D ( double  p1[3],
double  p2[3],
int &  localId 
)
protected

Return 1 if the parent of edge defined by vertices (`p1',`p2') in parametric coordinates, is an edge; 3 if there is no parent (the edge is inside). If the parent is an edge, return its id in `localId'.

Precondition
p1!=p2
p1 and p2 are in bounding box (0,0,0) (1,1,1)
Postcondition
valid_result: (result==1)||(result==3)
int vtkSimpleCellTessellator::FindEdgeParent ( double  p1[3],
double  p2[3],
int &  localId 
)
protected

Return 1 if the parent of edge defined by vertices (`p1',`p2') in parametric coordinates, is an edge; 2 if the parent is a face, 3 if there is no parent (the edge is inside). If the parent is an edge or a face, return its id in `localId'.

Precondition
p1!=p2
p1 and p2 are in bounding box (0,0,0) (1,1,1)
Postcondition
valid_result: result>=1 && result<=3
void vtkSimpleCellTessellator::AllocatePointIds ( int  size)
protected

Allocate some memory if PointIds does not exist or is smaller than size.

Precondition
positive_size: size>0
int vtkSimpleCellTessellator::FacesAreEqual ( int *  originalFace,
int  face[3] 
)
protected

Are the faces `originalFace' and `face' equal? The result is independent from any order or orientation.

Precondition
originalFace_exists: originalFace!=0

Friends And Related Function Documentation

friend class vtkTetraTile
friend

Definition at line 356 of file vtkSimpleCellTessellator.h.

friend class vtkTriangleTile
friend

Definition at line 357 of file vtkSimpleCellTessellator.h.

Member Data Documentation

vtkGenericEdgeTable* vtkSimpleCellTessellator::EdgeTable
protected

HashTable instead of vtkPointLocator

Definition at line 188 of file vtkSimpleCellTessellator.h.

vtkGenericAdaptorCell* vtkSimpleCellTessellator::GenericCell
protected

To access the higher order cell from third party library

Definition at line 236 of file vtkSimpleCellTessellator.h.

double* vtkSimpleCellTessellator::Scalars
protected

Scalar buffer used to save the interpolate values of the attributes The capacity is at least the number of components of the attribute collection ot the current cell.

Definition at line 252 of file vtkSimpleCellTessellator.h.

int vtkSimpleCellTessellator::ScalarsCapacity
protected

Definition at line 253 of file vtkSimpleCellTessellator.h.

int vtkSimpleCellTessellator::PointOffset
protected

Number of double value to skip to go to the next point into Scalars array It is 6+attributeCollection->GetNumberOfComponents()

Definition at line 257 of file vtkSimpleCellTessellator.h.

vtkGenericCellIterator* vtkSimpleCellTessellator::CellIterator
protected

Used to iterate over edges boundaries in GetNumberOfCellsUsingEdges()

Definition at line 260 of file vtkSimpleCellTessellator.h.

vtkGenericAttributeCollection* vtkSimpleCellTessellator::AttributeCollection
protected

To access the higher order field from third party library

Definition at line 263 of file vtkSimpleCellTessellator.h.

vtkDoubleArray* vtkSimpleCellTessellator::TessellatePoints
protected

To avoid New/Delete

Definition at line 267 of file vtkSimpleCellTessellator.h.

vtkCellArray* vtkSimpleCellTessellator::TessellateCellArray
protected

To avoid New/Delete

Definition at line 268 of file vtkSimpleCellTessellator.h.

vtkPointData* vtkSimpleCellTessellator::TessellatePointData
protected

To avoid New/Delete

Definition at line 269 of file vtkSimpleCellTessellator.h.

vtkGenericDataSet* vtkSimpleCellTessellator::DataSet
protected

Dataset to be tessellated.

Definition at line 313 of file vtkSimpleCellTessellator.h.

vtkIdType vtkSimpleCellTessellator::NumberOfPoints
protected

Number of points in the dataset to be tessellated.

Definition at line 316 of file vtkSimpleCellTessellator.h.

int vtkSimpleCellTessellator::FixedSubdivisions
protected

Definition at line 318 of file vtkSimpleCellTessellator.h.

int vtkSimpleCellTessellator::MaxSubdivisionLevel
protected

Definition at line 319 of file vtkSimpleCellTessellator.h.

int vtkSimpleCellTessellator::CurrentSubdivisionLevel
protected

Definition at line 320 of file vtkSimpleCellTessellator.h.

int* vtkSimpleCellTessellator::EdgeIds
protected

For each edge (6) of the sub-tetra, there is the id of the original edge or -1 if the edge is not an original edge

Definition at line 325 of file vtkSimpleCellTessellator.h.

int* vtkSimpleCellTessellator::FaceIds
protected

For each edge (6) of the sub-tetra, there is the id of the original edge or -1 if the edge is not an original edge

Definition at line 329 of file vtkSimpleCellTessellator.h.

vtkOrderedTriangulator* vtkSimpleCellTessellator::Triangulator
protected

Definition at line 336 of file vtkSimpleCellTessellator.h.

vtkCellArray* vtkSimpleCellTessellator::Connectivity
protected

Definition at line 340 of file vtkSimpleCellTessellator.h.

vtkPolygon* vtkSimpleCellTessellator::Polygon
protected

Definition at line 343 of file vtkSimpleCellTessellator.h.

vtkIdList* vtkSimpleCellTessellator::TriangleIds
protected

Definition at line 346 of file vtkSimpleCellTessellator.h.

vtkIdType* vtkSimpleCellTessellator::PointIds
protected

Definition at line 348 of file vtkSimpleCellTessellator.h.

int vtkSimpleCellTessellator::PointIdsCapacity
protected

Definition at line 349 of file vtkSimpleCellTessellator.h.


The documentation for this class was generated from the following file: