[Paraview] Random Colormap

[Scott, W Alan]

Random color maps really aren't that hard to create, using a trick.  Basically, you split the color map into ranges, for instance 0-0.1=black, 0.100001-0.2=blue, etc.

Here is a random color map that uses 24 colors.  Notice that this isn't perfect, but it works pretty well.  You can test it using disk_out_ref.exo, and looking at color.  Obviously, you can easily break this into more colors.

Cut and paste the following XML into a file, for instance colorMap24Random.xml.
Open your object.
Edit Color Map/ Choose Preset/ Import/ colorMap24Random.xml.


The other way may be to make a "random number variable" using your partitions number as input.  This is done using the calculator and some random number formula.  For an example, see the ParaView wiki, ParaView 3 Tutorial, Beginning Filters, Calculator.  http://paraview.org/Wiki/ParaView.

Alan


<ColorMap name="25 Random Colors" space="RGB">

<Point x="0.000" o="1" r="1.0" g="0.0" b="0.0"/>

<Point x="0.040" o="1" r="1.0" g="0.0" b="0.0"/>

<Point x="0.041" o="1" r="0.0" g="1.0" b="0.0"/>

<Point x="0.080" o="1" r="0.0" g="1.0" b="0.0"/>

<Point x="0.081" o="1" r="0.0" g="0.0" b="1.0"/>

<Point x="0.120" o="1" r="0.0" g="0.0" b="1.0"/>

<Point x="0.121" o="1" r="1.0" g="1.0" b="0.0"/>

<Point x="0.160" o="1" r="1.0" g="1.0" b="0.0"/>

<Point x="0.161" o="1" r="1.0" g="0.0" b="1.0"/>

<Point x="0.200" o="1" r="1.0" g="0.0" b="1.0"/>

<Point x="0.201" o="1" r="0.0" g="1.0" b="1.0"/>

<Point x="0.240" o="1" r="0.0" g="1.0" b="1.0"/>

<Point x="0.241" o="1" r="0.5" g="0.0" b="0.0"/>

<Point x="0.280" o="1" r="0.5" g="0.0" b="0.0"/>

<Point x="0.281" o="1" r="0.0" g="0.5" b="0.0"/>

<Point x="0.320" o="1" r="0.0" g="0.5" b="0.0"/>

<Point x="0.321" o="1" r="0.0" g="0.0" b="0.5"/>

<Point x="0.360" o="1" r="0.0" g="0.0" b="0.5"/>

<Point x="0.361" o="1" r="0.5" g="1.0" b="0.0"/>

<Point x="0.400" o="1" r="0.5" g="1.0" b="0.0"/>

<Point x="0.401" o="1" r="0.5" g="0.0" b="1.0"/>

<Point x="0.440" o="1" r="0.5" g="0.0" b="1.0"/>

<Point x="0.441" o="1" r="0.0" g="0.5" b="1.0"/>

<Point x="0.480" o="1" r="0.0" g="0.5" b="1.0"/>

<Point x="0.481" o="1" r="0.75" g="0.0" b="0.0"/>

<Point x="0.520" o="1" r="0.75" g="0.0" b="0.0"/>

<Point x="0.521" o="1" r="0.0" g="0.75" b="0.0"/>

<Point x="0.560" o="1" r="0.0" g="0.75" b="0.0"/>

<Point x="0.561" o="1" r="0.0" g="0.0" b="0.75"/>

<Point x="0.600" o="1" r="0.0" g="0.0" b="0.75"/>

<Point x="0.601" o="1" r="0.75" g="1.0" b="0.0"/>

<Point x="0.640" o="1" r="0.75" g="1.0" b="0.0"/>

<Point x="0.641" o="1" r="0.75" g="0.0" b="1.0"/>

<Point x="0.680" o="1" r="0.75" g="0.0" b="1.0"/>

<Point x="0.681" o="1" r="0.0" g="0.75" b="1.0"/>

<Point x="0.720" o="1" r="0.0" g="0.75" b="1.0"/>

<Point x="0.721" o="1" r="0.25" g="0.0" b="0.0"/>

<Point x="0.760" o="1" r="0.25" g="0.0" b="0.0"/>

<Point x="0.761" o="1" r="0.0" g="0.25" b="0.0"/>

<Point x="0.800" o="1" r="0.0" g="0.25" b="0.0"/>

<Point x="0.801" o="1" r="0.0" g="0.0" b="0.25"/>

<Point x="0.840" o="1" r="0.0" g="0.0" b="0.25"/>

<Point x="0.841" o="1" r="0.25" g="1.0" b="0.0"/>

<Point x="0.880" o="1" r="0.25" g="1.0" b="0.0"/>

<Point x="0.881" o="1" r="0.25" g="0.0" b="1.0"/>

<Point x="0.920" o="1" r="0.25" g="0.0" b="1.0"/>

<Point x="0.921" o="1" r="1.0" g="0.0" b="0.25"/>

<Point x="0.960" o="1" r="1.0" g="0.0" b="0.25"/>

<Point x="0.961" o="1" r="0.0" g="0.25" b="1.0"/>

<Point x="1.000" o="1" r="0.0" g="0.25" b="1.0"/>

</ColorMap>

________________________________
From: paraview-bounces at paraview.org [mailto:paraview-bounces at paraview.org] On Behalf Of Chaman Singh Verma
Sent: Saturday, December 20, 2008 10:50 AM
To: paraview at paraview.org
Subject: [Paraview] Random Colormap

Hello,

I have one specific requirement and hope ParaView can do a good job. I am interested in
Visualizing Graph Partitioned Domain. Since number of Partitions could be very large,
it is important that neighbouring domain to have high contrasting color. A smoothly
varying colormap doesn't do good job for large domains.

Is there any way to create random colormap in ParaView ?

Thanks.
csv

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