<div dir="ltr"><div class="markdown-here-wrapper" style="font-family:"Lucida Sans",Cantarell,Verdana,sans-serif;color:rgb(11,83,148)"><p style="margin:0px 0px 1.2em!important">Hi,</p>
<p style="margin:0px 0px 1.2em!important">In short, VTK’s support for label map masks is limited.</p>
<p style="margin:0px 0px 1.2em!important">I’m not sure what you mean by opacity. If you see the documentation for <a href="https://www.vtk.org/doc/nightly/html/classvtkGPUVolumeRayCastMapper.html#a57d26b71335b8d904cf1adde6ba976b6"><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-radius:3px;display:inline">vtkGPUVolumeRayCastMapper::SetMaskInput</code></a>, it explains how the final sample color is determined.</p>
<p style="margin:0px 0px 1.2em!important">As to why it works the way it does, I’ll defer to the authors but more likely, this was all that was required from the mapper at the time it was written.</p>
<p style="margin:0px 0px 1.2em!important">The mapper might actually work(I’ve not tested this, but should, in general) with N number of components given that <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-radius:3px;display:inline">vtkProperty::IndependentComponents</code> is set. The limitation of a maximum of 4 components is when they are treated as dependent.</p>
<p style="margin:0px 0px 1.2em!important">Hope this helps.</p>
<p style="margin:0px 0px 1.2em!important">Thanks,<br>Sankhesh</p>
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Although subject is clear enough, but I want to know what's the reasons of<br>
these limitations?<br>
I found out that vtk supports up to 4 components in label map volume<br>
rendering (with mask). I can set colors for each component, but just first<br>
opacity (index=0) will applied and others will be ignored. Is there<br>
technical issue for controlling each component opacity separately?<br>
My last question, why number of components is restricted to four? seems the<br>
overhead of a few transfer functions is not too much.<br>
<br>
<br>
<br>
--<br>
Sent from: <a href="http://vtk.1045678.n5.nabble.com/VTK-Users-f1224199.html" rel="noreferrer" target="_blank">http://vtk.1045678.n5.nabble.com/VTK-Users-f1224199.html</a><br>
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</blockquote></div>-- <br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div class="inbox-inbox-inbox-inbox-inbox-inbox-inbox-markdown-here-wrapper" style="font-family:"proza libre",sans-serif;color:rgb(0,56,107)"><h5 id="inbox-inbox-inbox-inbox-inbox-inbox-inbox-sankhesh-jhaveri" style="margin:1.3em 0px 1em;padding:0px;font-size:1.1em;border-bottom-width:1px;border-bottom-style:solid;border-bottom-color:rgb(238,238,238);font-weight:bold;color:rgb(11,65,148)">Sankhesh Jhaveri</h5>
<h6 id="inbox-inbox-inbox-inbox-inbox-inbox-inbox--sr-research-development-engineer-kitware-http-www-kitware-com-518-881-4417" style="margin:1.3em 0px 1em;padding:0px;font-size:1em;color:rgb(11,83,148);font-family:"open sans",sans-serif;font-weight:normal"><em>Sr. Research & Development Engineer</em> | <a href="http://www.kitware.com/">Kitware</a> | (518) 881-4417</h6>
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