vtkMapper

Section: Visualization Toolkit Rendering Classes

Usage

vtkMapper is an abstract class to specify interface between data and graphics primitives. Subclasses of vtkMapper map data through a lookuptable and control the creation of rendering primitives that interface to the graphics library. The mapping can be controlled by supplying a lookup table and specifying a scalar range to map data through.

There are several important control mechanisms affecting the behavior of this object. The ScalarVisibility flag controls whether scalar data (if any) controls the color of the associated actor(s) that refer to the mapper. The ScalarMode ivar is used to determine whether scalar point data or cell data is used to color the object. By default, point data scalars are used unless there are none, in which cell scalars are used. Or you can explicitly control whether to use point or cell scalar data. Finally, the mapping of scalars through the lookup table varies depending on the setting of the ColorMode flag. See the documentation for the appropriate methods for an explanation.

Another important feature of this class is whether to use immediate mode rendering (ImmediateModeRenderingOn) or display list rendering (ImmediateModeRenderingOff). If display lists are used, a data structure is constructed (generally in the rendering library) which can then be rapidly traversed and rendered by the rendering library. The disadvantage of display lists is that they require additionally memory which may affect the performance of the system.

Another important feature of the mapper is the ability to shift the z-buffer to resolve coincident topology. For example, if you'd like to draw a mesh with some edges a different color, and the edges lie on the mesh, this feature can be useful to get nice looking lines. (See the ResolveCoincidentTopology-related methods.)

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

  obj = vtkMapper

Methods

The class vtkMapper 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 vtkMapper class.