<div dir="ltr"><div class="markdown-here-wrapper" style="font-family:'Lucida Sans',Verdana,sans-serif;color:rgb(11,83,148)"><p style="margin:0px 0px 1.2em!important">Hi Evan,</p>
<p style="margin:0px 0px 1.2em!important">This is already supported in VTK for the volume mapper. You can have a single array with either 2 components and set them as dependent components via <a href="http://www.vtk.org/doc/nightly/html/classvtkVolumeProperty.html#aea26cdad334f47cf078c3ab9f1b70764">vtkVolumeProperty</a>. This feature is not exposed in ParaView but it would just be a matter of creating the GUI elements and adding a filtering step to combine two arrays into a single two-component array.</p>
<p style="margin:0px 0px 1.2em!important">For polygonal data, can’t think of a better route than the one suggested by Utkarsh i.e. manually map the arrays through the lookup tables and create an RGBA array. Make sure to uncheck <code style="font-size:0.95em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(218,218,218);background-color:rgb(232,232,232);border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;display:inline">Map Scalars</code> to use the RGBA values directly. Having said that, this can also be implemented as a feature on the <code style="font-size:0.95em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(218,218,218);background-color:rgb(232,232,232);border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;display:inline">vtkPolyDataMapper</code> similar to the volume mapper.</p>
<p style="margin:0px 0px 1.2em!important">Hope that helps,<br>Sankhesh</p>
<blockquote style="margin:1.2em 0px;border-left-width:4px;border-left-style:solid;border-left-color:rgb(221,221,221);padding:0px 1em;color:rgb(119,119,119);quotes:none"><br>From: Utkarsh Ayachit <a href="http://mailto:[utkarsh.ayachit@kitware.com](mailto:utkarsh.ayachit@kitware.com)">[utkarsh.ayachit@kitware.com](mailto:utkarsh.ayachit@kitware.com)</a><br>To: Evan Kao <a href="http://mailto:[tossin@gmail.com](mailto:tossin@gmail.com)">[tossin@gmail.com](mailto:tossin@gmail.com)</a><br>Cc: ParaView <a href="http://mailto:[paraview@paraview.org](mailto:paraview@paraview.org)">[paraview@paraview.org](mailto:paraview@paraview.org)</a><br>Bcc:<br>Date: Thu, 29 Jun 2017 10:55:45 -0400<br>Subject: Re: [Paraview] Use separate arrays for colormap and opacity<br>One option is to use “Python Programmable Filter” to generate an RGBA<br>array in which you do the color and opacity mapping yourself. You<br>won’t have access to the color and opacity transfer ParaView sets up,<br>but you can create your own internally. Not the most elegant solution<br>— but a solution, nonetheless.<br><br>Utkarsh<br><br></blockquote><div title="MDH:PGRpdj48c3BhbiBzdHlsZT0iZm9udC1zaXplOiAxM3B4OyI+SGkgRXZhbiw8L3NwYW4+PC9kaXY+
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