vtkProgrammableGlyphFilter - control the generation and placement of glyphs at input points

Super Class: vtkDataSetToPolyDataFilter

Description:

vtkProgrammableGlyphFilter is a filter that allows you to place a glyph at each input point in the dataset. In addition, the filter is programmable which means the user has control over the generation of the glyph. The glyphs can be controlled via the point data attributes (e.g., scalars, vectors, etc.) or any other information in the input dataset. This is the way the filter works. You must define an input dataset which at a minimum contains points with associated attribute values. Also, the Source instance variable must be set which is of type vtkPolyData. Then, for each point in the input, the PointId is set to the current point id, and a user-defined function is called (i.e., GlyphMethod). In this method you can manipulate the Source data (including changing to a different Source object). After the GlyphMethod is called, vtkProgrammableGlyphFilter will invoke an Update() on its Source object, and then copy its data to the output of the vtkProgrammableGlyphFilter. Therefore the output of this filter is of type vtkPolyData. Another option to this filter is the way you color the glyphs. You can use the scalar data from the input or the source. The instance variable ColorMode controls this behavior.

Caveats:

This filter operates on point data attributes. If you want to use cell data attributes, use a filter like vtkCellCenters to generate points at the centers of cells, and then use these points. Note that the data attributes (cell and point) are passed to the output of this filter from the Source object. This works well as long as you are not changing the class of the Source object during execution. However, if the class of the Source object changes, then the potential exists that the data attributes might change during execution (e.g., scalars available from one source and not the next), possibly fouling up the copying of data attributes to the output. In this case, you may have to manually set the output's copy flags (e.g., CopyScalarsOn/Off(), CopyVectorsOn/Off(), etc.) to control what's being copied.

See Also:

vtkGlyph3D vtkTensorGlyph vtkCellCenters

Methods:

Detailed Method Descriptions: