vtkIncrementalOctreePointLocator

Section: Visualization Toolkit Filtering Classes

Usage

As opposed to the uniform bin-based search structure (adopted in class vtkPointLocator) with a fixed spatial resolution, an octree mechanism employs a hierarchy of tree-like sub-division of the 3D data domain. Thus it enables data-aware multi-resolution and accordingly accelerated point location as well as insertion, particularly when handling a radically imbalanced layout of points as not uncommon in datasets defined on adaptive meshes. Compared to a static point locator supporting pure location functionalities through some search structure established from a fixed set of points, an incremental point locator allows for, in addition, point insertion capabilities, with the search structure maintaining a dynamically increasing number of points. Class vtkIncrementalOctreePointLocator is an octree-based accelerated implementation of the functionalities of the uniform bin-based incremental point locator vtkPointLocator. For point location, an octree is built by accessing a vtkDataSet, specifically a vtkPointSet. For point insertion, an empty octree is inited and then incrementally populated as points are inserted. Three increasingly complex point insertion modes, i.e., direct check-free insertion, zero tolerance insertion, and non-zero tolerance insertion, are supported. In fact, the octree used in the point location mode is actually constructed via direct check-free point insertion. This class also provides a polygonal representation of the octree boundary.

To create an instance of class vtkIncrementalOctreePointLocator, simply invoke its constructor as follows

  obj = vtkIncrementalOctreePointLocator

Methods

The class vtkIncrementalOctreePointLocator has several methods that can be used. They are listed below. Note that the documentation is translated automatically from the VTK sources, and may not be completely intelligible. When in doubt, consult the VTK website. In the methods listed below, obj is an instance of the vtkIncrementalOctreePointLocator class.