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Hello Julian,<br><br>
You might want to try using vtkColorTransferFunction instead of
vtkLookupTable. This allows you to add points of color (in RGB or HSV
space) and interpolate linearly between them (in RGB or HSV). The points
do not need to be evenly spaced. <br><br>
Lisa<br><br>
<br><br>
At 11:56 PM 9/24/2002, julianholt wrote:<br>
<blockquote type=cite class=cite cite><font size=2>Guys</font><br>
<br>
<font size=2>I have a normalised vtk dataset (values from 0.0 to 1.0)
containing up to 500,000 scalar values that is written to a vtk
file.</font><br>
<br>
<font size=2>I need to plot this, using different user definable colours
(lookup table).</font><br>
<br>
<font size=2><u>Question</u></font><br>
<br>
<font size=2>Is there anyway within a vtk file to specify a non-linear
lookup table?</font><br>
<br>
<font size=2>From my experiments, if you have say 10 colours in a lookup
table each "band" is 0.1</font><br>
<br>
<font size=2>What I would like to say is, "set band 1 to plot
between 1.0 to 0.5 and let the remaining 9 bands cover the 0.0 - 0.5
level".</font><br>
<br>
<font size=2>Make sense?</font><br>
<br>
<font size=2>Doesn't look to me that you can do this in a vtk file
without changing the data (ouch) OR adding many more than 10 colours to
the lookup table.</font><br>
<br>
<font size=2>Many thanks for any pointers</font><br>
<br>
<br>
<font size=2>Julian Holt </font><br>
<font size=2><a href="http://www.fatiguewizard.com">www.fatiguewizard.com</a></font></blockquote></html>