This module edits the fourth component of a multichannel lattice. It can be used to set the alpha channel of a colormap to a set of discrete values, which can be useful when volume rendering a data array.

The component is set as follows:

alpha(i) = 0.0;           0 <= i <  Limit1;
         = Value1;   Limit1 <= i <  Limit2;
         = Value2;   Limit2 <= i <  Limit3;
         = Value3;   Limit3 <= i <  N;
where N is the number of entries in the colormap (i.e., the value of dims[0] for the lattice).


Port: Input Colormap
Type: Lattice
Constraints: 1-D
Input colormap.


Port: Value1
Type: Dial
Component value for indices Limit1 through Limit2-1.

Port: Value2
Type: Dial
Component value for indices Limit2 through Limit3-1.

Port: Value3
Type: Dial
Component value for indices Limit3 through N-1.

Port: Limit1
Type: Slider
End of first range of indices.

Port: Limit2
Type: Slider
End of second range of indices.

Port: Limit3
Type: Slider
End of third range of indices.


Port: Output Colormap
Type: Lattice
Output colormap, with modified alpha channel.



VolumeRender, VolumeToGeom.

Note: the VolumeRender module is not available for all ports of IRIS Explorer.

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© The Numerical Algorithms Group Ltd, Oxford UK. 2000