vtkCoordinate

Section: Visualization Toolkit Filtering Classes

Usage

vtkCoordinate represents position in a variety of coordinate systems, and converts position to other coordinate systems. It also supports relative positioning, so you can create a cascade of vtkCoordinate objects (no loops please!) that refer to each other. The typical usage of this object is to set the coordinate system in which to represent a position (e.g., SetCoordinateSystemToNormalizedDisplay()), set the value of the coordinate (e.g., SetValue()), and then invoke the appropriate method to convert to another coordinate system (e.g., GetComputedWorldValue()). The coordinate systems in vtk are as follows: <PRE> DISPLAY - x-y pixel values in window NORMALIZED DISPLAY - x-y (0,1) normalized values VIEWPORT - x-y pixel values in viewport NORMALIZED VIEWPORT - x-y (0,1) normalized value in viewport VIEW - x-y-z (-1,1) values in camera coordinates. (z is depth) WORLD - x-y-z global coordinate values USERDEFINED - x-y-z in User defined space </PRE>

If you cascade vtkCoordinate objects, you refer to another vtkCoordinate object which in turn can refer to others, and so on. This allows you to create composite groups of things like vtkActor2D that are positioned relative to one another. Note that in cascaded sequences, each vtkCoordinate object may be specified in different coordinate systems!

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

  obj = vtkCoordinate

Methods

The class vtkCoordinate 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 vtkCoordinate class.