vtkGenericAdaptorCell

Section: Visualization Toolkit Filtering Classes

Usage

In VTK, spatial-temporal data is defined in terms of a dataset which is composed of cells. The cells are topological entities over which an interpolation field is applied. Cells are defined in terms of a topology (e.g., vertices, lines, triangles, polygons, tetrahedra, etc.), points that instantiate the geometry of the cells, and interpolation fields (in the general case one interpolation field is for geometry, the other is for attribute data associated with the cell).

Currently most algorithms in VTK use vtkCell and vtkDataSet, which make assumptions about the nature of datasets, cells, and attributes. In particular, this abstraction assumes that cell interpolation functions are linear, or products of linear functions. Further, VTK implements most of the interpolation functions. This implementation starts breaking down as the complexity of the interpolation (or basis) functions increases.

vtkGenericAdaptorCell addresses these issues by providing more general abstraction for cells. It also adopts modern C++ practices including using iterators. The vtkGenericAdaptorCell is designed to fit within the adaptor framework; meaning that it is meant to adapt VTK to external simulation systems (see the GenericFiltering/README.html).

Please note that most cells are defined in terms of other cells (the boundary cells). They are also defined in terms of points, which are not the same as vertices (vertices are a 0-D cell; points represent a position in space).

Another important concept is the notion of DOFNodes. These concept supports cell types with complex interpolation functions. For example, higher-order p-method finite elements may have different functions on each of their topological features (edges, faces, region). The coefficients of these polynomial functions are associated with DOFNodes. (There is a single DOFNode for each topological feature.) Note that from this perspective, points are used to establish the topological form of the cell; mid-side nodes and such are considered DOFNodes.

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

  obj = vtkGenericAdaptorCell

Methods

The class vtkGenericAdaptorCell 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 vtkGenericAdaptorCell class.