#include <vtkOBBTree.h>
Inheritance diagram for vtkOBBTree:
vtkOBBTree is an object to generate oriented bounding box (OBB) trees. An oriented bounding box is a bounding box that does not necessarily line up along coordinate axes. The OBB tree is a hierarchical tree structure of such boxes, where deeper levels of OBB confine smaller regions of space.
To build the OBB, a recursive, topdown process is used. First, the root OBB is constructed by finding the mean and covariance matrix of the cells (and their points) that define the dataset. The eigenvectors of the covariance matrix are extracted, giving a set of three orthogonal vectors that define the tightestfitting OBB. To create the two children OBB's, a split plane is found that (approximately) divides the number cells in half. These are then assigned to the children OBB's. This process then continues until the MaxLevel ivar limits the recursion, or no split plane can be found.
A good reference for OBBtrees is Gottschalk & Manocha in Proceedings of Siggraph `96.
Long, skinny cells (i.e., cells with poor aspect ratio) may cause unsatisfactory results. This is due to the fact that this is a topdown implementation of the OBB tree, requiring that one or more complete cells are contained in each OBB. This requirement makes it hard to find good split planes during the recursion process. A bottomup implementation would go a long way to correcting this problem.
Definition at line 82 of file vtkOBBTree.h.
void  ComputeOBB (vtkPoints *pts, double corner[3], double max[3], double mid[3], double min[3], double size[3]) 
static vtkOBBTree *  New () 
Public Types  
typedef vtkCellLocator  Superclass 
Public Member Functions  
virtual const char *  GetClassName () 
virtual int  IsA (const char *type) 
void  PrintSelf (ostream &os, vtkIndent indent) 
int  IntersectWithLine (double a0[3], double a1[3], double tol, double &t, double x[3], double pcoords[3], int &subId, vtkIdType &cellId) 
void  GenerateRepresentation (int level, vtkPolyData *pd) 
void  ComputeOBB (vtkDataSet *input, double corner[3], double max[3], double mid[3], double min[3], double size[3]) 
int  InsideOrOutside (const double point[3]) 
int  IntersectWithLine (const double a0[3], const double a1[3], vtkPoints *points, vtkIdList *cellIds) 
int  IntersectWithLine (double a0[3], double a1[3], double tol, double &t, double x[3], double pcoords[3], int &subId) 
int  IntersectWithLine (double a0[3], double a1[3], double tol, double &t, double x[3], double pcoords[3], int &subId, vtkIdType &cellId, vtkGenericCell *cell) 
int  DisjointOBBNodes (vtkOBBNode *nodeA, vtkOBBNode *nodeB, vtkMatrix4x4 *XformBtoA) 
int  LineIntersectsNode (vtkOBBNode *pA, double b0[3], double b1[3]) 
int  TriangleIntersectsNode (vtkOBBNode *pA, double p0[3], double p1[3], double p2[3], vtkMatrix4x4 *XformBtoA) 
int  IntersectWithOBBTree (vtkOBBTree *OBBTreeB, vtkMatrix4x4 *XformBtoA, int(*function)(vtkOBBNode *nodeA, vtkOBBNode *nodeB, vtkMatrix4x4 *Xform, void *arg), void *data_arg) 
void  FreeSearchStructure () 
void  BuildLocator () 
Static Public Member Functions  
static int  IsTypeOf (const char *type) 
static vtkOBBTree *  SafeDownCast (vtkObject *o) 
Protected Member Functions  
vtkOBBTree ()  
~vtkOBBTree ()  
void  ComputeOBB (vtkIdList *cells, double corner[3], double max[3], double mid[3], double min[3], double size[3]) 
void  BuildTree (vtkIdList *cells, vtkOBBNode *parent, int level) 
void  DeleteTree (vtkOBBNode *OBBptr) 
void  GeneratePolygons (vtkOBBNode *OBBptr, int level, int repLevel, vtkPoints *pts, vtkCellArray *polys) 
Protected Attributes  
vtkOBBNode *  Tree 
vtkPoints *  PointsList 
int *  InsertedPoints 
int  OBBCount 
int  DeepestLevel 

Reimplemented from vtkCellLocator. Definition at line 85 of file vtkOBBTree.h. 





Reimplemented from vtkCellLocator. 

Return 1 if this class type is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeRevisionMacro found in vtkSetGet.h. Reimplemented from vtkCellLocator. 

Return 1 if this class is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeRevisionMacro found in vtkSetGet.h. Reimplemented from vtkCellLocator. 

Reimplemented from vtkCellLocator. 

Methods invoked by print to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes. Reimplemented from vtkCellLocator. 

Construct with automatic computation of divisions, averaging 25 cells per octant. Reimplemented from vtkCellLocator. 

Compute an OBB from the list of points given. Return the corner point and the three axes defining the orientation of the OBB. Also return a sorted list of relative "sizes" of axes for comparison purposes. 

Compute an OBB for the input dataset using the cells in the data. Return the corner point and the three axes defining the orientation of the OBB. Also return a sorted list of relative "sizes" of axes for comparison purposes. 

Determine whether a point is inside or outside the data used to build this OBB tree. The data must be a closed surface vtkPolyData data set. The return value is +1 if outside, 1 if inside, and 0 if undecided. 

Take the passed line segment and intersect it with the data set. 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. 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. Either 'points' or 'cellIds' can be set to NULL if you don't want to receive that information. 

Return the first intersection of the specified line segment with the OBB tree, as well as information about the cell which the line segment intersected. Reimplemented from vtkCellLocator. 

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

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. Reimplemented from vtkCellLocator. 

Returns true if nodeB and nodeA are disjoint after optional transformation of nodeB with matrix XformBtoA 

Returns true if line intersects node. 

Returns true if triangle (optionally transformed) intersects node. 

For each intersecting leaf node pair, call function. OBBTreeB is optionally transformed by XformBtoA before testing. 

Satisfy locator's abstract interface, see vtkLocator. Reimplemented from vtkCellLocator. 

Satisfy locator's abstract interface, see vtkLocator. Reimplemented from vtkCellLocator. 

Create polygonal representation for OBB tree at specified level. If level < 0, then the leaf OBB nodes will be gathered. The aspect ratio (ar) and line diameter (d) are used to control the building of the representation. If a OBB node edge ratio's are greater than ar, then the dimension of the OBB is collapsed (OBB>plane>line). A "line" OBB will be represented either as two crossed polygons, or as a line, depending on the relative diameter of the OBB compared to the diameter (d). Reimplemented from vtkCellLocator. 









Reimplemented from vtkCellLocator. Definition at line 203 of file vtkOBBTree.h. 

Definition at line 205 of file vtkOBBTree.h. 

Definition at line 206 of file vtkOBBTree.h. 

Definition at line 207 of file vtkOBBTree.h. 

Definition at line 208 of file vtkOBBTree.h. 