vtkPolyData
StructuredPoints
A subclass of ImageData.
StructuredPoints is a subclass of ImageData that requires the data extent to exactly match the update extent. Normall image data allows that the data extent may be larger than the update extent. StructuredPoints also defines the origin differently that vtkImageData. For structured points the origin is the location of first point. Whereas images define the origin as the location of point 0, 0, 0. Image Origin is stored in ivar, and structured points have special methods for setting/getting the origin/extents.
vtkTriangleStrip
a cell that represents a triangle strip
vtkTriangleStrip is a concrete implementation of vtkCell to represent a 2D triangle strip. A triangle strip is a compact representation of triangles connected edge to edge in strip fashion. The connectivity of a triangle strip is three points defining an initial triangle, then for each additional triangle, a single point that, combined with the previous two points, defines the next triangle.
vtkPolyData
concrete dataset represents vertices, lines, polygons, and triangle strips
vtkPolyData is a data object that is a concrete implementation of vtkDataSet. vtkPolyData represents a geometric structure consisting of vertices, lines, polygons, and/or triangle strips. Point and cell attribute values (e.g., scalars, vectors, etc.) also are represented.
The actual cell types (vtkCellType.h) supported by vtkPolyData are: vtkVertex, vtkPolyVertex, vtkLine, vtkPolyLine, vtkTriangle, vtkQuad, vtkPolygon, and vtkTriangleStrip.
One important feature of vtkPolyData objects is that special traversal and data manipulation methods are available to process data. These methods are generally more efficient than vtkDataSet methods and should be used whenever possible. For example, traversing the cells in a dataset we would use GetCell(). To traverse cells with vtkPolyData we would retrieve the cell array object representing polygons (for example using GetPolys()) and then use vtkCellArray's InitTraversal() and GetNextCell() methods.
Warning:
Because vtkPolyData is implemented with four separate instances of vtkCellArray to represent 0D vertices, 1D lines, 2D polygons, and 2D triangle strips, it is possible to create vtkPolyData instances that consist of a mixture of cell types. Because of the design of the class, there are certain limitations on how mixed cell types are inserted into the vtkPolyData, and in turn the order in which they are processed and rendered. To preserve the consistency of cell ids, and to insure that cells with cell data are rendered properly, users must insert mixed cells in the order of vertices (vtkVertex and vtkPolyVertex), lines (vtkLine and vtkPolyLine), polygons (vtkTriangle, vtkQuad, vtkPolygon), and triangle strips (vtkTriangleStrip).
Some filters when processing vtkPolyData with mixed cell types may process the cells in differing ways. Some will convert one type into another (e.g., vtkTriangleStrip into vtkTriangles) or expect a certain type (vtkDecimatePro expects triangles or triangle strips; vtkTubeFilter expects lines). Read the documentation for each filter carefully to understand how each part of vtkPolyData is processed.
