
 Usage

vtkScalarsToColors is a general purpose superclass for
objects that convert scalars to colors. This include
vtkLookupTable classes and color transfer functions.
The scalars to color mapping can be augmented with an
additional uniform alpha blend. This is used, for example,
to blend a vtkActor's opacity with the lookup table values.
To create an instance of class vtkScalarsToColors, simply
invoke its constructor as follows

    obj = vtkScalarsToColors



 Methods

The class vtkScalarsToColors 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 vtkScalarsToColors class.

* string = obj.GetClassName ()
* int = obj.IsA (string name)
* vtkScalarsToColors = obj.NewInstance ()
* vtkScalarsToColors = obj.SafeDownCast (vtkObject o)
* int = obj.IsOpaque () - Return true if all of the values
  defining the mapping have an opacity equal to 1. Default
  implementation return true.
* obj.Build () - Perform any processing required (if any)
  before processing scalars.
* double = obj.GetRange () - Sets/Gets the range of scalars
  which will be mapped.
* obj.SetRange (double min, double max) - Sets/Gets the
  range of scalars which will be mapped.
* obj.SetRange (double rng[2]) - Map one value through the
  lookup table and return a color defined as a RGBA unsigned
  char tuple (4 bytes).
* obj.GetColor (double v, double rgb[3]) - Map one value
  through the lookup table and return the color as an RGB
  array of doubles between 0 and 1.
* double = obj.GetColor (double v) - Map one value through
  the lookup table and return the alpha value (the opacity)
  as a double between 0 and 1.
* double = obj.GetOpacity (double ) - Map one value through
  the lookup table and return the luminance 0.3*red +
  0.59*green + 0.11*blue as a double between 0 and 1.
  Returns the luminance value for the specified scalar
  value.
* double = obj.GetLuminance (double x) - Specify an
  additional opacity (alpha) value to blend with. Values !=
  1 modify the resulting color consistent with the requested
  form of the output. This is typically used by an actor in
  order to blend its opacity.
* obj.SetAlpha (double alpha) - Specify an additional
  opacity (alpha) value to blend with. Values != 1 modify
  the resulting color consistent with the requested form of
  the output. This is typically used by an actor in order to
  blend its opacity.
* double = obj.GetAlpha () - Specify an additional opacity
  (alpha) value to blend with. Values != 1 modify the
  resulting color consistent with the requested form of the
  output. This is typically used by an actor in order to
  blend its opacity.
* vtkUnsignedCharArray = obj.MapScalars (vtkDataArray
  scalars, int colorMode, int component) - An internal
  method maps a data array into a 4-component, unsigned char
  RGBA array. The color mode determines the behavior of
  mapping. If VTK_COLOR_MODE_DEFAULT is set, then unsigned
  char data arrays are treated as colors (and converted to
  RGBA if necessary); otherwise, the data is mapped through
  this instance of ScalarsToColors. The offset is used for
  data arrays with more than one component; it indicates
  which component to use to do the blending. When the
  component argument is -1, then the this object uses its
  own selected technique to change a vector into a scalar to
  map.
* obj.SetVectorMode (int ) - Change mode that maps vectors
  by magnitude vs. component.
* int = obj.GetVectorMode () - Change mode that maps vectors
  by magnitude vs. component.
* obj.SetVectorModeToMagnitude () - Change mode that maps
  vectors by magnitude vs. component.
* obj.SetVectorModeToComponent () - Change mode that maps
  vectors by magnitude vs. component.
* obj.SetVectorComponent (int ) - If the mapper does not
  select which component of a vector to map to colors, you
  can specify it here.
* int = obj.GetVectorComponent () - If the mapper does not
  select which component of a vector to map to colors, you
  can specify it here.
* obj.MapScalarsThroughTable (vtkDataArray scalars, string
  output, int outputFormat) - Map a set of scalars through
  the lookup table in a single operation. The output format
  can be set to VTK_RGBA (4 components), VTK_RGB (3
  components), VTK_LUMINANCE (1 component, greyscale), or
  VTK_LUMINANCE_ALPHA (2 components) If not supplied, the
  output format defaults to RGBA.
* obj.MapScalarsThroughTable (vtkDataArray scalars, string
  output) - An internal method typically not used in
  applications.
* vtkUnsignedCharArray = obj.ConvertUnsignedCharToRGBA
  (vtkUnsignedCharArray colors, int numComp, int numTuples)
  - An internal method used to convert a color array to
  RGBA. The method instantiates a vtkUnsignedCharArray and
  returns it. The user is responsible for managing the
  memory.
* int = obj.UsingLogScale () - This should return 1 is the
  subclass is using log scale for mapping scalars to colors.
  Default implementation returns 0.


* FreeMat_Documentation
* Visualization_Toolkit_Common_Classes
* Generated on Thu Jul 25 2013 17:18:30 for FreeMat by
  doxygen_ 1.8.1.1

