Generate axis aligned BBox tree for ray-casting and other Locator based searches. More...

#include <vtkModifiedBSPTree.h>

Inheritance diagram for vtkModifiedBSPTree:

Collaboration diagram for vtkModifiedBSPTree:

Public Member Functions
int	IntersectWithLine (const double p1[3], const double p2[3], double tol, double &t, double x[3], double pcoords[3], int &subId, vtkIdType &cellId, vtkGenericCell *cell) override
	Return intersection point (if any) AND the cell which was intersected by the finite line.

int	IntersectWithLine (const double p1[3], const double p2[3], double tol, vtkPoints points, vtkIdList cellIds, vtkGenericCell *cell) override
	Take the passed line segment and intersect it with the data set.

void	FindCellsAlongLine (const double p1[3], const double p2[3], double tolerance, vtkIdList *cellsIds) override
	Take the passed line segment and intersect it with the data set.

vtkIdType	FindCell (double x[3], double vtkNotUsed(tol2), vtkGenericCell GenCell, int &subId, double pcoords[3], double weights) override
	Find the cell containing a given point.

vtkIdListCollection *	GetLeafNodeCellInformation ()
	After subdivision has completed, one may wish to query the tree to find which cells are in which leaf nodes.

virtual void	GenerateRepresentationLeafs (vtkPolyData *pd)
	Generate BBox representation of all leaf nodes.

void	ShallowCopy (vtkAbstractCellLocator *locator) override
	Shallow copy of a vtkModifiedBSPTree.

virtual vtkIdType	FindCell (double x[3])
	Returns the Id of the cell containing the point, returns -1 if no cell found.

virtual vtkIdType	FindCell (double x[3], double tol2, vtkGenericCell GenCell, double pcoords[3], double weights)
	Find the cell containing a given point.

virtual vtkIdType	FindCell (double x[3], double tol2, vtkGenericCell GenCell, int &subId, double pcoords[3], double weights)
	Find the cell containing a given point.

virtual int	IntersectWithLine (const double p1[3], const double p2[3], double tol, double &t, double x[3], double pcoords[3], int &subId)
	Return intersection point (if any) of finite line with cells contained in cell locator.

virtual int	IntersectWithLine (const double p1[3], const double p2[3], double tol, double &t, double x[3], double pcoords[3], int &subId, vtkIdType &cellId)
	Return intersection point (if any) AND the cell which was intersected by the finite line.

virtual int	IntersectWithLine (const double p1[3], const double p2[3], double tol, double &t, double x[3], double pcoords[3], int &subId, vtkIdType &cellId, vtkGenericCell *cell)
	Return intersection point (if any) AND the cell which was intersected by the finite line.

virtual int	IntersectWithLine (const double p1[3], const double p2[3], vtkPoints points, vtkIdList cellIds)
	Take the passed line segment and intersect it with the data set.

virtual int	IntersectWithLine (const double p1[3], const double p2[3], double tol, vtkPoints points, vtkIdList cellIds)
	Take the passed line segment and intersect it with the data set.

virtual int	IntersectWithLine (const double p1[3], const double p2[3], double tol, vtkPoints points, vtkIdList cellIds, vtkGenericCell *cell)
	Take the passed line segment and intersect it with the data set.


void	GenerateRepresentation (int level, vtkPolyData *pd) override
	Satisfy vtkLocator abstract interface.

void	FreeSearchStructure () override
	Satisfy vtkLocator abstract interface.

void	BuildLocator () override
	Satisfy vtkLocator abstract interface.

void	ForceBuildLocator () override
	Satisfy vtkLocator abstract interface.

Public Member Functions inherited from vtkAbstractCellLocator
virtual vtkTypeBool	IsA (const char *type)
	Standard type and print methods.

vtkAbstractCellLocator *	NewInstance () const

void	PrintSelf (ostream &os, vtkIndent indent) override
	Methods invoked by print to print information about the object including superclasses.

void	ComputeCellBounds ()
	This function can be used either internally or externally to compute only the cached cell bounds if CacheCellBounds is on.

virtual int	IntersectWithLine (const double p1[3], const double p2[3], double tol, double &t, double x[3], double pcoords[3], int &subId)
	Return intersection point (if any) of finite line with cells contained in cell locator.

virtual int	IntersectWithLine (const double p1[3], const double p2[3], double tol, double &t, double x[3], double pcoords[3], int &subId, vtkIdType &cellId)
	Return intersection point (if any) AND the cell which was intersected by the finite line.

virtual int	IntersectWithLine (const double p1[3], const double p2[3], double tol, double &t, double x[3], double pcoords[3], int &subId, vtkIdType &cellId, vtkGenericCell *cell)
	Return intersection point (if any) AND the cell which was intersected by the finite line.

virtual int	IntersectWithLine (const double p1[3], const double p2[3], vtkPoints points, vtkIdList cellIds)
	Take the passed line segment and intersect it with the data set.

virtual int	IntersectWithLine (const double p1[3], const double p2[3], double tol, vtkPoints points, vtkIdList cellIds)
	Take the passed line segment and intersect it with the data set.

virtual int	IntersectWithLine (const double p1[3], const double p2[3], double tol, vtkPoints points, vtkIdList cellIds, vtkGenericCell *cell)
	Take the passed line segment and intersect it with the data set.

virtual void	FindClosestPoint (const double x[3], double closestPoint[3], vtkIdType &cellId, int &subId, double &dist2)
	Return the closest point and the cell which is closest to the point x.

virtual void	FindClosestPoint (const double x[3], double closestPoint[3], vtkGenericCell *cell, vtkIdType &cellId, int &subId, double &dist2)
	Return the closest point and the cell which is closest to the point x.

virtual vtkIdType	FindClosestPointWithinRadius (double x[3], double radius, double closestPoint[3], vtkIdType &cellId, int &subId, double &dist2)
	Return the closest point within a specified radius and the cell which is closest to the point x.

virtual vtkIdType	FindClosestPointWithinRadius (double x[3], double radius, double closestPoint[3], vtkGenericCell *cell, vtkIdType &cellId, int &subId, double &dist2)
	Return the closest point within a specified radius and the cell which is closest to the point x.

virtual vtkIdType	FindClosestPointWithinRadius (double x[3], double radius, double closestPoint[3], vtkGenericCell *cell, vtkIdType &cellId, int &subId, double &dist2, int &inside)
	Return the closest point within a specified radius and the cell which is closest to the point x.

virtual void	FindCellsWithinBounds (double bbox, vtkIdList cells)
	Return a list of unique cell ids inside of a given bounding box.

virtual void	FindCellsAlongLine (const double p1[3], const double p2[3], double tolerance, vtkIdList *cells)
	Take the passed line segment and intersect it with the data set.

virtual void	FindCellsAlongPlane (const double o[3], const double n[3], double tolerance, vtkIdList *cells)
	Given an unbounded plane defined by an origin o[3] and unit normal n[3], return the list of unique cell ids in the buckets containing the plane.

virtual vtkIdType	FindCell (double x[3])
	Returns the Id of the cell containing the point, returns -1 if no cell found.

virtual bool	InsideCellBounds (double x[3], vtkIdType cell_ID)
	Quickly test if a point is inside the bounds of a particular cell.

virtual void	ShallowCopy (vtkAbstractCellLocator *)
	Shallow copy of a vtkAbstractCellLocator.

virtual void	SetNumberOfCellsPerNode (int)
	Specify the preferred/maximum number of cells in each node/bucket.

virtual int	GetNumberOfCellsPerNode ()
	Specify the preferred/maximum number of cells in each node/bucket.

virtual void	SetCacheCellBounds (vtkTypeBool)
	Boolean controls whether the bounds of each cell are computed only once and then saved.

virtual vtkTypeBool	GetCacheCellBounds ()
	Boolean controls whether the bounds of each cell are computed only once and then saved.

virtual void	CacheCellBoundsOn ()
	Boolean controls whether the bounds of each cell are computed only once and then saved.

virtual void	CacheCellBoundsOff ()
	Boolean controls whether the bounds of each cell are computed only once and then saved.

virtual void	SetRetainCellLists (vtkTypeBool)
	Boolean controls whether to maintain list of cells in each node.

virtual vtkTypeBool	GetRetainCellLists ()
	Boolean controls whether to maintain list of cells in each node.

virtual void	RetainCellListsOn ()
	Boolean controls whether to maintain list of cells in each node.

virtual void	RetainCellListsOff ()
	Boolean controls whether to maintain list of cells in each node.

Public Member Functions inherited from vtkLocator
virtual void	Update ()
	Cause the locator to rebuild itself if it or its input dataset has changed.

virtual void	Initialize ()
	Initialize locator.

virtual void	BuildLocator ()=0
	Build the locator from the input dataset.

virtual void	ForceBuildLocator ()
	Build the locator from the input dataset (even if UseExistingSearchStructure is on).

virtual void	FreeSearchStructure ()=0
	Free the memory required for the spatial data structure.

virtual void	GenerateRepresentation (int level, vtkPolyData *pd)=0
	Method to build a representation at a particular level.

virtual void	SetDataSet (vtkDataSet *)
	Build the locator from the points/cells defining this dataset.

virtual vtkDataSet *	GetDataSet ()
	Build the locator from the points/cells defining this dataset.

virtual void	SetMaxLevel (int)
	Set the maximum allowable level for the tree.

virtual int	GetMaxLevel ()
	Set the maximum allowable level for the tree.

virtual int	GetLevel ()
	Get the level of the locator (determined automatically if Automatic is true).

virtual void	SetAutomatic (vtkTypeBool)
	Boolean controls whether locator depth/resolution of locator is computed automatically from average number of entities in bucket.

virtual vtkTypeBool	GetAutomatic ()
	Boolean controls whether locator depth/resolution of locator is computed automatically from average number of entities in bucket.

virtual void	AutomaticOn ()
	Boolean controls whether locator depth/resolution of locator is computed automatically from average number of entities in bucket.

virtual void	AutomaticOff ()
	Boolean controls whether locator depth/resolution of locator is computed automatically from average number of entities in bucket.

virtual void	SetTolerance (double)
	Specify absolute tolerance (in world coordinates) for performing geometric operations.

virtual double	GetTolerance ()
	Specify absolute tolerance (in world coordinates) for performing geometric operations.

virtual void	SetUseExistingSearchStructure (vtkTypeBool)
	Get/Set UseExistingSearchStructure, which when enabled it allows the locator to NOT be built again.

virtual vtkTypeBool	GetUseExistingSearchStructure ()
	Get/Set UseExistingSearchStructure, which when enabled it allows the locator to NOT be built again.

virtual void	UseExistingSearchStructureOn ()
	Get/Set UseExistingSearchStructure, which when enabled it allows the locator to NOT be built again.

virtual void	UseExistingSearchStructureOff ()
	Get/Set UseExistingSearchStructure, which when enabled it allows the locator to NOT be built again.

virtual vtkMTimeType	GetBuildTime ()
	Return the time of the last data structure build.

bool	UsesGarbageCollector () const override
	Handle the PointSet <-> Locator loop.

vtkLocator *	NewInstance () const
	Standard type and print methods.

Public Member Functions inherited from vtkObject
	vtkBaseTypeMacro (vtkObject, vtkObjectBase)

virtual void	DebugOn ()
	Turn debugging output on.

virtual void	DebugOff ()
	Turn debugging output off.

bool	GetDebug ()
	Get the value of the debug flag.

void	SetDebug (bool debugFlag)
	Set the value of the debug flag.

virtual void	Modified ()
	Update the modification time for this object.

virtual vtkMTimeType	GetMTime ()
	Return this object's modified time.

void	PrintSelf (ostream &os, vtkIndent indent) override
	Methods invoked by print to print information about the object including superclasses.

void	RemoveObserver (unsigned long tag)

void	RemoveObservers (unsigned long event)

void	RemoveObservers (const char *event)

void	RemoveAllObservers ()

vtkTypeBool	HasObserver (unsigned long event)

vtkTypeBool	HasObserver (const char *event)

vtkTypeBool	InvokeEvent (unsigned long event)

vtkTypeBool	InvokeEvent (const char *event)

std::string	GetObjectDescription () const override
	The object description printed in messages and PrintSelf output.

unsigned long	AddObserver (unsigned long event, vtkCommand *, float priority=0.0f)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

unsigned long	AddObserver (const char event, vtkCommand , float priority=0.0f)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

vtkCommand *	GetCommand (unsigned long tag)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

void	RemoveObserver (vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

void	RemoveObservers (unsigned long event, vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

void	RemoveObservers (const char event, vtkCommand )
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

vtkTypeBool	HasObserver (unsigned long event, vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

vtkTypeBool	HasObserver (const char event, vtkCommand )
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, void(T::*callback)(), float priority=0.0f)
	Overloads to AddObserver that allow developers to add class member functions as callbacks for events.

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, void(T::callback)(vtkObject , unsigned long, void *), float priority=0.0f)
	Overloads to AddObserver that allow developers to add class member functions as callbacks for events.

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, bool(T::callback)(vtkObject , unsigned long, void *), float priority=0.0f)
	Allow user to set the AbortFlagOn() with the return value of the callback method.

vtkTypeBool	InvokeEvent (unsigned long event, void *callData)
	This method invokes an event and return whether the event was aborted or not.

vtkTypeBool	InvokeEvent (const char event, void callData)
	This method invokes an event and return whether the event was aborted or not.

virtual void	SetObjectName (const std::string &objectName)
	Set/get the name of this object for reporting purposes.

virtual std::string	GetObjectName () const
	Set/get the name of this object for reporting purposes.

Public Member Functions inherited from vtkObjectBase
const char *	GetClassName () const
	Return the class name as a string.

virtual std::string	GetObjectDescription () const
	The object description printed in messages and PrintSelf output.

virtual vtkTypeBool	IsA (const char *name)
	Return 1 if this class is the same type of (or a subclass of) the named class.

virtual vtkIdType	GetNumberOfGenerationsFromBase (const char *name)
	Given the name of a base class of this class type, return the distance of inheritance between this class type and the named class (how many generations of inheritance are there between this class and the named class).

virtual void	Delete ()
	Delete a VTK object.

virtual void	FastDelete ()
	Delete a reference to this object.

void	InitializeObjectBase ()

void	Print (ostream &os)
	Print an object to an ostream.

void	Register (vtkObjectBase *o)
	Increase the reference count (mark as used by another object).

virtual void	UnRegister (vtkObjectBase *o)
	Decrease the reference count (release by another object).

int	GetReferenceCount ()
	Return the current reference count of this object.

void	SetReferenceCount (int)
	Sets the reference count.

bool	GetIsInMemkind () const
	A local state flag that remembers whether this object lives in the normal or extended memory space.

virtual void	PrintHeader (ostream &os, vtkIndent indent)
	Methods invoked by print to print information about the object including superclasses.

virtual void	PrintTrailer (ostream &os, vtkIndent indent)
	Methods invoked by print to print information about the object including superclasses.

Static Public Member Functions
static vtkModifiedBSPTree *	New ()
	Construct with maximum 32 cells per node.

Static Public Member Functions inherited from vtkAbstractCellLocator
static vtkTypeBool	IsTypeOf (const char *type)

static vtkAbstractCellLocator *	SafeDownCast (vtkObjectBase *o)

Static Public Member Functions inherited from vtkLocator
static vtkTypeBool	IsTypeOf (const char *type)
	Standard type and print methods.

static vtkLocator *	SafeDownCast (vtkObjectBase *o)
	Standard type and print methods.

Static Public Member Functions inherited from vtkObject
static vtkObject *	New ()
	Create an object with Debug turned off, modified time initialized to zero, and reference counting on.

static void	BreakOnError ()
	This method is called when vtkErrorMacro executes.

static void	SetGlobalWarningDisplay (vtkTypeBool val)
	This is a global flag that controls whether any debug, warning or error messages are displayed.

static void	GlobalWarningDisplayOn ()
	This is a global flag that controls whether any debug, warning or error messages are displayed.

static void	GlobalWarningDisplayOff ()
	This is a global flag that controls whether any debug, warning or error messages are displayed.

static vtkTypeBool	GetGlobalWarningDisplay ()
	This is a global flag that controls whether any debug, warning or error messages are displayed.

Static Public Member Functions inherited from vtkObjectBase
static vtkTypeBool	IsTypeOf (const char *name)
	Return 1 if this class type is the same type of (or a subclass of) the named class.

static vtkIdType	GetNumberOfGenerationsFromBaseType (const char *name)
	Given a the name of a base class of this class type, return the distance of inheritance between this class type and the named class (how many generations of inheritance are there between this class and the named class).

static vtkObjectBase *	New ()
	Create an object with Debug turned off, modified time initialized to zero, and reference counting on.

static void	SetMemkindDirectory (const char *directoryname)
	The name of a directory, ideally mounted -o dax, to memory map an extended memory space within.

static bool	GetUsingMemkind ()
	A global state flag that controls whether vtkObjects are constructed in the usual way (the default) or within the extended memory space.

Protected Member Functions
	vtkModifiedBSPTree ()

	~vtkModifiedBSPTree () override

void	BuildLocatorInternal () override
	This function is not pure virtual to maintain backwards compatibility.

void	Subdivide (BSPNode node, Sorted_cell_extents_Lists lists, vtkDataSet *dataSet, vtkIdType nCells, int depth, int maxlevel, vtkIdType maxCells, int &MaxDepth)

Protected Member Functions inherited from vtkAbstractCellLocator
virtual vtkObjectBase *	NewInstanceInternal () const
	Standard type and print methods.

	vtkAbstractCellLocator ()

	~vtkAbstractCellLocator () override

void	UpdateInternalWeights ()
	To be called in `FindCell(double[3])`.

void	GetCellBounds (vtkIdType cellId, double *&cellBoundsPtr)

virtual bool	StoreCellBounds ()
	This command is used internally by the locator to copy all cell Bounds into the internal CellBounds array.

virtual void	FreeCellBounds ()
	This command is used internally by the locator to copy all cell Bounds into the internal CellBounds array.

Protected Member Functions inherited from vtkLocator
	vtkLocator ()

	~vtkLocator () override

virtual void	BuildLocatorInternal ()
	This function is not pure virtual to maintain backwards compatibility.

void	ReportReferences (vtkGarbageCollector *) override

Protected Member Functions inherited from vtkObject
	vtkObject ()

	~vtkObject () override

void	RegisterInternal (vtkObjectBase *, vtkTypeBool check) override

void	UnRegisterInternal (vtkObjectBase *, vtkTypeBool check) override

void	InternalGrabFocus (vtkCommand mouseEvents, vtkCommand keypressEvents=nullptr)
	These methods allow a command to exclusively grab all events.

void	InternalReleaseFocus ()
	These methods allow a command to exclusively grab all events.

Protected Member Functions inherited from vtkObjectBase
	vtkObjectBase ()

virtual	~vtkObjectBase ()

virtual void	RegisterInternal (vtkObjectBase *, vtkTypeBool check)

virtual void	UnRegisterInternal (vtkObjectBase *, vtkTypeBool check)

virtual void	ReportReferences (vtkGarbageCollector *)

virtual void	ObjectFinalize ()

	vtkObjectBase (const vtkObjectBase &)

void	operator= (const vtkObjectBase &)

Protected Attributes
std::shared_ptr< BSPNode >	mRoot

int	npn

int	nln

int	tot_depth

Protected Attributes inherited from vtkAbstractCellLocator
int	NumberOfCellsPerNode

vtkTypeBool	RetainCellLists

vtkTypeBool	CacheCellBounds

vtkNew< vtkGenericCell >	GenericCell

std::shared_ptr< std::vector< double > >	CellBoundsSharedPtr

double *	CellBounds

vtkTimeStamp	WeightsTime
	This time stamp helps us decide if we want to update internal `Weights` array size.

std::vector< double >	Weights
	This array is resized so that it can fit points from the cell hosting the most in the input data set.

Protected Attributes inherited from vtkLocator
vtkDataSet *	DataSet

vtkTypeBool	UseExistingSearchStructure

vtkTypeBool	Automatic

double	Tolerance

int	MaxLevel

int	Level

vtkTimeStamp	BuildTime

Protected Attributes inherited from vtkObject
bool	Debug

vtkTimeStamp	MTime

vtkSubjectHelper *	SubjectHelper

std::string	ObjectName

Protected Attributes inherited from vtkObjectBase
std::atomic< int32_t >	ReferenceCount

vtkWeakPointerBase **	WeakPointers

typedef vtkAbstractCellLocator	Superclass
	Standard methods to print and obtain type-related information.

static vtkTypeBool	IsTypeOf (const char *type)
	Standard methods to print and obtain type-related information.

static vtkModifiedBSPTree *	SafeDownCast (vtkObjectBase *o)
	Standard methods to print and obtain type-related information.

virtual vtkTypeBool	IsA (const char *type)
	Standard methods to print and obtain type-related information.

vtkModifiedBSPTree *	NewInstance () const
	Standard methods to print and obtain type-related information.

void	PrintSelf (ostream &os, vtkIndent indent) override
	Standard methods to print and obtain type-related information.

virtual vtkObjectBase *	NewInstanceInternal () const
	Standard methods to print and obtain type-related information.

Additional Inherited Members
Public Types inherited from vtkAbstractCellLocator
typedef vtkLocator	Superclass

Public Types inherited from vtkLocator
typedef vtkObject	Superclass
	Standard type and print methods.

Static Protected Member Functions inherited from vtkAbstractCellLocator
static bool	IsInBounds (const double bounds[6], const double x[3], double tol=0.0)

Static Protected Member Functions inherited from vtkObjectBase
static vtkMallocingFunction	GetCurrentMallocFunction ()

static vtkReallocingFunction	GetCurrentReallocFunction ()

static vtkFreeingFunction	GetCurrentFreeFunction ()

static vtkFreeingFunction	GetAlternateFreeFunction ()

Detailed Description

Generate axis aligned BBox tree for ray-casting and other Locator based searches.

vtkModifiedBSPTree creates an evenly balanced BSP tree using a top down implementation. Axis aligned split planes are found which evenly divide cells into two buckets. Generally a split plane will intersect some cells and these are usually stored in both child nodes of the current parent. (Or split into separate cells which we cannot consider in this case). Storing cells in multiple buckets creates problems associated with multiple tests against rays and increases the required storage as complex meshes will have many cells straddling a split plane (and further splits may cause multiple copies of these).

During a discussion with Arno Formella in 1998 he suggested using a third child node to store objects which straddle split planes. I've not seen this published (Yes! - see below), but thought it worth trying. This implementation of the BSP tree creates a third child node for storing cells laying across split planes, the third cell may overlap the other two, but the two 'proper' nodes otherwise conform to usual BSP rules.

The advantage of this implementation is cells only ever lie in one node and mailbox testing is avoided. All BBoxes are axis aligned and a ray cast uses an efficient search strategy based on near/far nodes and rejects all BBoxes using simple tests.

For fast raytracing, 6 copies of cell lists are stored in each leaf node each list is in axis sorted order +/- x,y,z and cells are always tested in the direction of the ray dominant axis. Once an intersection is found any cell or BBox with a closest point further than the I-point can be instantly rejected and raytracing stops as soon as no nodes can be closer than the current best intersection point.

The addition of the 'middle' node upsets the optimal balance of the tree, but is a minor overhead during the raytrace. Each child node is contracted such that it tightly fits all cells inside it, enabling further ray/box rejections.

This class is intended for persons requiring many ray tests and is optimized for this purpose. As no cell ever lies in more than one leaf node, and parent nodes do not maintain cell lists, the memory overhead of the sorted cell lists is 6*num_cells*4 for 6 lists of ints, each num_cells in length. The memory requirement of the nodes themselves is usually of minor significance.

Subdivision is controlled by MaxCellsPerNode - any node with more than this number will be subdivided providing a good split plane can be found and the max depth is not exceeded.

The average cells per leaf will usually be around half the MaxCellsPerNode, though the middle node is usually sparsely populated and lowers the average slightly. The middle node will not be created when not needed. Subdividing down to very small cells per node is not generally suggested as then the 6 stored cell lists are effectively redundant.

Values of MaxCellsPerNode of around 16->128 depending on dataset size will usually give good results.

Cells are only sorted into 6 lists once - before tree creation, each node segments the lists and passes them down to the new child nodes whilst maintaining sorted order. This makes for an efficient subdivision strategy.

Warning

vtkModifiedBSPTree utilizes the following parent class parameters:

Level (default 8)
MaxLevel (default 8)
NumberOfCellsPerNode (default 32)
UseExistingSearchStructure (default false)
CacheCellBounds (default true)

vtkModifiedBSPTree does NOT utilize the following parameters:

Automatic
Tolerance
RetainCellLists

NB. The following reference has been sent to me

@Article{formella-1995-ray,
  author =     "Arno Formella and Christian Gill",
  title =      "{Ray Tracing: A Quantitative Analysis and a New
                Practical Algorithm}",
  journal =    "{The Visual Computer}",
  year =       "{1995}",
  month =       dec,
  pages =      "{465--476}",
  volume =     "{11}",
  number =     "{9}",
  publisher =  "{Springer}",
  keywords =   "{ray tracing, space subdivision, plane traversal,
                 octree, clustering, benchmark scenes}",
  annote =     "{We present a new method to accelerate the process of
                 finding nearest ray--object intersections in ray
                 tracing. The algorithm consumes an amount of memory
                 more or less linear in the number of objects. The basic
                 ideas can be characterized with a modified BSP--tree
                 and plane traversal. Plane traversal is a fast linear
                 time algorithm to find the closest intersection point
                 in a list of bounding volumes hit by a ray. We use
                 plane traversal at every node of the high outdegree
                 BSP--tree. Our implementation is competitive to fast
                 ray tracing programs. We present a benchmark suite
                 which allows for an extensive comparison of ray tracing
                 algorithms.}",
}

Thanks:: John Biddiscombe for developing and contributing this class

@todo

Implement intersection heap for testing rays against transparent objects

@par Style:

This class is currently maintained by J. Biddiscombe who has specially requested that the code style not be modified to the Kitware standard. Please respect the contribution of this class by keeping the style as close as possible to the author's original.

See also: vtkAbstractCellLocator vtkCellLocator vtkStaticCellLocator vtkCellTreeLocator vtkOBBTree

Online Examples:

DataStructureComparison

ModifiedBSPTreeExtractCells

ModifiedBSPTreeIntersectWithLine

ModifiedBSPTreeTimingDemo

VisualizeModifiedBSPTree

Tests:: vtkModifiedBSPTree (Tests)

Definition at line 205 of file vtkModifiedBSPTree.h.

Member Typedef Documentation

◆ Superclass

typedef vtkAbstractCellLocator vtkModifiedBSPTree::Superclass

Standard methods to print and obtain type-related information.

Definition at line 212 of file vtkModifiedBSPTree.h.

Constructor & Destructor Documentation

◆ vtkModifiedBSPTree()

vtkModifiedBSPTree::vtkModifiedBSPTree ( )

protected

◆ ~vtkModifiedBSPTree()

vtkModifiedBSPTree::~vtkModifiedBSPTree ( )

overrideprotected

Member Function Documentation

◆ IsTypeOf()

static vtkTypeBool vtkModifiedBSPTree::IsTypeOf ( const char * type )

static

Standard methods to print and obtain type-related information.

◆ IsA()

virtual vtkTypeBool vtkModifiedBSPTree::IsA ( const char * type )

virtual

Standard methods to print and obtain type-related information.

Reimplemented from vtkAbstractCellLocator.

◆ SafeDownCast()

static vtkModifiedBSPTree * vtkModifiedBSPTree::SafeDownCast ( vtkObjectBase * o )

static

Standard methods to print and obtain type-related information.

◆ NewInstanceInternal()

virtual vtkObjectBase * vtkModifiedBSPTree::NewInstanceInternal ( ) const

protectedvirtual

Standard methods to print and obtain type-related information.

Reimplemented from vtkAbstractCellLocator.

◆ NewInstance()

vtkModifiedBSPTree * vtkModifiedBSPTree::NewInstance ( ) const

Standard methods to print and obtain type-related information.

◆ PrintSelf()

void vtkModifiedBSPTree::PrintSelf	(	ostream &	os,
		vtkIndent	indent
	)

overridevirtual

Standard methods to print and obtain type-related information.

Reimplemented from vtkAbstractCellLocator.

◆ New()

static vtkModifiedBSPTree * vtkModifiedBSPTree::New ( )

static

Construct with maximum 32 cells per node.

(average 16->31)

◆ IntersectWithLine() [1/8]

int vtkModifiedBSPTree::IntersectWithLine	(	const double	p1[3],
		const double	p2[3],
		double	tol,
		double &	t,
		double	x[3],
		double	pcoords[3],
		int &	subId,
		vtkIdType &	cellId,
		vtkGenericCell *	cell
	)

overridevirtual

Return intersection point (if any) AND the cell which was intersected by the finite line.

The cell is returned as a cell id and as a generic cell.

For other IntersectWithLine signatures, see vtkAbstractCellLocator.

Reimplemented from vtkAbstractCellLocator.

◆ IntersectWithLine() [2/8]

int vtkModifiedBSPTree::IntersectWithLine	(	const double	p1[3],
		const double	p2[3],
		double	tol,
		vtkPoints *	points,
		vtkIdList *	cellIds,
		vtkGenericCell *	cell
	)

overridevirtual

Take the passed line segment and intersect it with the data set.

The return value of the function is 0 if no intersections were found. For each intersection with the bounds of a cell or with a cell (if a cell is provided), the points and cellIds have the relevant information added sorted by t. If points or cellIds are nullptr pointers, then no information is generated for that list.

For other IntersectWithLine signatures, see vtkAbstractCellLocator.

Reimplemented from vtkAbstractCellLocator.

◆ FindCellsAlongLine()

void vtkModifiedBSPTree::FindCellsAlongLine	(	const double	p1[3],
		const double	p2[3],
		double	tolerance,
		vtkIdList *	cellsIds
	)

inlineoverridevirtual

Take the passed line segment and intersect it with the data set.

For each intersection with the bounds of a cell, the cellIds have the relevant information added sort by t. If cellIds is nullptr pointer, then no information is generated for that list.

Reimplemented from vtkAbstractCellLocator to showcase that it's a supported function.

Reimplemented from vtkAbstractCellLocator.

Definition at line 254 of file vtkModifiedBSPTree.h.

◆ FindCell() [1/4]

vtkIdType vtkModifiedBSPTree::FindCell	(	double	x[3],
		double	vtkNotUsedtol2,
		vtkGenericCell *	GenCell,
		int &	subId,
		double	pcoords[3],
		double *	weights
	)

override

Find the cell containing a given point.

returns -1 if no cell found the cell parameters are copied into the supplied variables, a cell must be provided to store the information.

For other FindCell signatures, see vtkAbstractCellLocator.

◆ GetLeafNodeCellInformation()

vtkIdListCollection * vtkModifiedBSPTree::GetLeafNodeCellInformation ( )

After subdivision has completed, one may wish to query the tree to find which cells are in which leaf nodes.

This function returns a list which holds a cell Id list for each leaf node.

◆ GenerateRepresentationLeafs()

virtual void vtkModifiedBSPTree::GenerateRepresentationLeafs ( vtkPolyData * pd )

virtual

Generate BBox representation of all leaf nodes.

◆ GenerateRepresentation()

void vtkModifiedBSPTree::GenerateRepresentation	(	int	level,
		vtkPolyData *	pd
	)

overridevirtual

Satisfy vtkLocator abstract interface.

Implements vtkLocator.

◆ FreeSearchStructure()

void vtkModifiedBSPTree::FreeSearchStructure ( )

overridevirtual

Satisfy vtkLocator abstract interface.

Implements vtkLocator.

◆ BuildLocator()

void vtkModifiedBSPTree::BuildLocator ( )

overridevirtual

Satisfy vtkLocator abstract interface.

Implements vtkLocator.

◆ ForceBuildLocator()

void vtkModifiedBSPTree::ForceBuildLocator ( )

overridevirtual

Satisfy vtkLocator abstract interface.

Reimplemented from vtkLocator.

◆ ShallowCopy()

void vtkModifiedBSPTree::ShallowCopy ( vtkAbstractCellLocator * locator )

overridevirtual

Shallow copy of a vtkModifiedBSPTree.

Before you shallow copy, make sure to call SetDataSet()

Reimplemented from vtkAbstractCellLocator.

◆ BuildLocatorInternal()

void vtkModifiedBSPTree::BuildLocatorInternal ( )

overrideprotectedvirtual

This function is not pure virtual to maintain backwards compatibility.

Reimplemented from vtkLocator.

◆ Subdivide()

void vtkModifiedBSPTree::Subdivide	(	BSPNode *	node,
		Sorted_cell_extents_Lists *	lists,
		vtkDataSet *	dataSet,
		vtkIdType	nCells,
		int	depth,
		int	maxlevel,
		vtkIdType	maxCells,
		int &	MaxDepth
	)

protected

◆ FindCell() [2/4]

virtual vtkIdType vtkAbstractCellLocator::FindCell ( double x[3] )

virtual

Returns the Id of the cell containing the point, returns -1 if no cell found.

This interface uses a tolerance of zero

THIS FUNCTION IS NOT THREAD SAFE.

Reimplemented from vtkAbstractCellLocator.

◆ FindCell() [3/4]

virtual vtkIdType vtkAbstractCellLocator::FindCell	(	double	x[3],
		double	tol2,
		vtkGenericCell *	GenCell,
		double	pcoords[3],
		double *	weights
	)

virtual

Find the cell containing a given point.

returns -1 if no cell found the cell parameters are copied into the supplied variables, a cell must be provided to store the information.

THIS FUNCTION IS THREAD SAFE.

Reimplemented from vtkAbstractCellLocator.

◆ FindCell() [4/4]

virtual vtkIdType vtkAbstractCellLocator::FindCell	(	double	x[3],
		double	tol2,
		vtkGenericCell *	GenCell,
		int &	subId,
		double	pcoords[3],
		double *	weights
	)

virtual

Find the cell containing a given point.

returns -1 if no cell found the cell parameters are copied into the supplied variables, a cell must be provided to store the information.

THIS FUNCTION IS THREAD SAFE.

Reimplemented from vtkAbstractCellLocator.

◆ IntersectWithLine() [3/8]

virtual int vtkAbstractCellLocator::IntersectWithLine	(	const double	p1[3],
		const double	p2[3],
		double	tol,
		double &	t,
		double	x[3],
		double	pcoords[3],
		int &	subId
	)

virtual

Return intersection point (if any) of finite line with cells contained in cell locator.

See vtkCell.h parameters documentation.

THIS FUNCTION IS NOT THREAD SAFE.

Reimplemented from vtkAbstractCellLocator.

◆ IntersectWithLine() [4/8]

virtual int vtkAbstractCellLocator::IntersectWithLine	(	const double	p1[3],
		const double	p2[3],
		double	tol,
		double &	t,
		double	x[3],
		double	pcoords[3],
		int &	subId,
		vtkIdType &	cellId
	)

virtual

Return intersection point (if any) AND the cell which was intersected by the finite line.

THIS FUNCTION IS NOT THREAD SAFE.

Reimplemented from vtkAbstractCellLocator.

◆ IntersectWithLine() [5/8]

virtual int vtkAbstractCellLocator::IntersectWithLine	(	const double	p1[3],
		const double	p2[3],
		double	tol,
		double &	t,
		double	x[3],
		double	pcoords[3],
		int &	subId,
		vtkIdType &	cellId,
		vtkGenericCell *	cell
	)

virtual

Return intersection point (if any) AND the cell which was intersected by the finite line.

The cell is returned as a cell id and as a generic cell.

This function takes in a vtkGenericCell to avoid using the internal vtkGenericCell.

THIS FUNCTION IS THREAD SAFE.

Reimplemented from vtkAbstractCellLocator.

◆ IntersectWithLine() [6/8]

virtual int vtkAbstractCellLocator::IntersectWithLine	(	const double	p1[3],
		const double	p2[3],
		vtkPoints *	points,
		vtkIdList *	cellIds
	)

virtual

Take the passed line segment and intersect it with the data set.

The return value of the function is 0 if no intersections were found, -1 if point 'a0' lies inside the closed surface, or +1 if point 'a0' lies outside the closed surface. This method assumes that the data set is a vtkPolyData that describes a closed surface, and the intersection points that are returned in 'points' alternate between entrance points and exit points.

Either 'points' or 'cellIds' can be set to nullptr if you don't want to receive that information.

This method is only implemented in vtkOBBTree.

THIS FUNCTION IS THREAD SAFE.

Reimplemented from vtkAbstractCellLocator.

◆ IntersectWithLine() [7/8]

virtual int vtkAbstractCellLocator::IntersectWithLine	(	const double	p1[3],
		const double	p2[3],
		double	tol,
		vtkPoints *	points,
		vtkIdList *	cellIds
	)

virtual

Take the passed line segment and intersect it with the data set.

The return value of the function is 0 if no intersections were found. For each intersection with a cell, the points and cellIds have the relevant information added sorted by t. If points or cellIds are nullptr pointers, then no information is generated for that list.

THIS FUNCTION IS NOT THREAD SAFE.

Reimplemented from vtkAbstractCellLocator.

◆ IntersectWithLine() [8/8]

virtual int vtkAbstractCellLocator::IntersectWithLine	(	const double	p1[3],
		const double	p2[3],
		double	tol,
		vtkPoints *	points,
		vtkIdList *	cellIds,
		vtkGenericCell *	cell
	)

virtual

Take the passed line segment and intersect it with the data set.

The return value of the function is 0 if no intersections were found. For each intersection with the bounds of a cell or with a cell (if a cell is provided), the points and cellIds have the relevant information added sorted by t. If points or cellIds are nullptr pointers, then no information is generated for that list.

This function takes in a vtkGenericCell to avoid using the internal vtkGenericCell.

THIS FUNCTION IS THREAD SAFE.

Reimplemented from vtkAbstractCellLocator.

Member Data Documentation

◆ mRoot

std::shared_ptr<BSPNode> vtkModifiedBSPTree::mRoot

protected

Definition at line 304 of file vtkModifiedBSPTree.h.

◆ npn

int vtkModifiedBSPTree::npn

protected

Definition at line 305 of file vtkModifiedBSPTree.h.

◆ nln

int vtkModifiedBSPTree::nln

protected

Definition at line 306 of file vtkModifiedBSPTree.h.

◆ tot_depth

int vtkModifiedBSPTree::tot_depth

protected

Definition at line 307 of file vtkModifiedBSPTree.h.

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

Filters/FlowPaths/vtkModifiedBSPTree.h

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

@todo

@par Style:

Member Typedef Documentation

◆ Superclass

Constructor & Destructor Documentation

◆ vtkModifiedBSPTree()

◆ ~vtkModifiedBSPTree()

Member Function Documentation

◆ IsTypeOf()

◆ IsA()

◆ SafeDownCast()

◆ NewInstanceInternal()

◆ NewInstance()

◆ PrintSelf()

◆ New()

◆ IntersectWithLine() [1/8]

◆ IntersectWithLine() [2/8]

◆ FindCellsAlongLine()

◆ FindCell() [1/4]

◆ GetLeafNodeCellInformation()

◆ GenerateRepresentationLeafs()

◆ GenerateRepresentation()

◆ FreeSearchStructure()

◆ BuildLocator()

◆ ForceBuildLocator()

◆ ShallowCopy()

◆ BuildLocatorInternal()

◆ Subdivide()

◆ FindCell() [2/4]

◆ FindCell() [3/4]

◆ FindCell() [4/4]

◆ IntersectWithLine() [3/8]

◆ IntersectWithLine() [4/8]

◆ IntersectWithLine() [5/8]

◆ IntersectWithLine() [6/8]

◆ IntersectWithLine() [7/8]

◆ IntersectWithLine() [8/8]

Member Data Documentation

◆ mRoot

◆ npn

◆ nln

◆ tot_depth