<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 Csaba,</p>
<p style="margin:0px 0px 1.2em!important">Programming wise, the missing component is support for calculating gradients across different volumes in the shader composer. </p>
<p style="margin:0px 0px 1.2em!important">Please feel free to report bugs on VTK’s issue tracker. If it is a relatively simple thing, we can fix it quickly. </p>
<p style="margin:0px 0px 1.2em!important">Thanks,<br>Sankhesh</p>
<div title="MDH:SGkgQ3NhYmEsPGRpdj48YnI+PC9kaXY+PGRpdj5Qcm9ncmFtbWluZyB3aXNlLCB0aGUgbWlzc2lu
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aXY+PGRpdj5TYW5raGVzaDwvZGl2Pg==" style="height:0;width:0;max-height:0;max-width:0;overflow:hidden;font-size:0em;padding:0;margin:0">​</div></div></div><br><div class="gmail_quote"><div dir="ltr">On Tue, Apr 24, 2018 at 9:15 AM Csaba Pinter <<a href="mailto:csaba.pinter@queensu.ca">csaba.pinter@queensu.ca</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">





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<p class="MsoNormal">Hi Sankhesh,<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Thanks for the quick answer! Just in a nutshell, what would be needed to do programming-wise to add shading in the code?<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Also I’m wondering if the situation about funding applies to bugfixes as well? I am struggling with issues related to per-volume visibility and user transforms, and I think I’ll get back to you soon with self-contained test cases once I
 was able to figure out which of these are on the VTK side and how to reproduce them easily.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Thanks,<u></u><u></u></p>
<p class="MsoNormal">csaba<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal" style="margin-left:.5in"><b>From:</b> Sankhesh Jhaveri <<a href="mailto:sankhesh.jhaveri@kitware.com" target="_blank">sankhesh.jhaveri@kitware.com</a>>
<br>
<b>Sent:</b> Monday, April 23, 2018 21:15<br>
<b>To:</b> Csaba Pinter <<a href="mailto:csaba.pinter@queensu.ca" target="_blank">csaba.pinter@queensu.ca</a>><br>
<b>Cc:</b> <a href="mailto:vtkusers@vtk.org" target="_blank">vtkusers@vtk.org</a><br>
<b>Subject:</b> Re: [vtkusers] vtkMultiVolume and shading<u></u><u></u></p></div></div><div lang="EN-US" link="blue" vlink="purple"><div class="m_3615127696476767924WordSection1">
<p class="MsoNormal" style="margin-left:.5in"><u></u> <u></u></p>
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<p style="margin-left:.5in"><span style="font-family:"Lucida Sans",sans-serif;color:#0b5394">Hi Csaba,<u></u><u></u></span></p>
<p style="margin-left:.5in;margin:1.2em!important"><span style="font-family:"Lucida Sans",sans-serif;color:#0b5394">I don’t believe there is a technical limitation. It was merely that the original effort for adding multiple overlapping volumes support was focused
 on selected features. I am not aware of current efforts/funding to add support for additional features like shading, different blend modes, etc.<u></u><u></u></span></p>
<p style="margin-left:.5in;margin:1.2em!important"><span style="font-family:"Lucida Sans",sans-serif;color:#0b5394">Thanks,<br>
Sankhesh<u></u><u></u></span></p>
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<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:1.0pt;font-family:"Arial",sans-serif;color:#0b5394">​</span><span style="font-size:1.0pt;font-family:"Lucida Sans",sans-serif;color:#0b5394"><u></u><u></u></span></p>
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<p class="MsoNormal" style="margin-left:.5in"><u></u> <u></u></p>
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<p class="MsoNormal" style="margin-left:.5in">On Mon, Apr 23, 2018 at 3:45 PM Csaba Pinter <<a href="mailto:csaba.pinter@queensu.ca" target="_blank">csaba.pinter@queensu.ca</a>> wrote:<u></u><u></u></p>
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Hello,<u></u><u></u></p>
<p class="MsoNormal" style="margin-left:.5in">
 <u></u><u></u></p>
<p class="MsoNormal" style="margin-left:.5in">
I’m experimenting with using vtkMultiVolume to add proper multi-volume rendering support into 3D Slicer. My main question is the reason behind this actor not supporting shading, as apparent when used, but also mentioned in the corresponding test:<u></u><u></u></p>
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<a href="https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2FKitware%2FVTK%2Fblob%2Fmaster%2FRendering%2FVolume%2FTesting%2FCxx%2FTestGPURayCastMultiVolumeOverlapping.cxx%23L229&data=02%7C01%7Ccsaba.pinter%40queensu.ca%7C8a6428523d3447bb73a508d5a980de7d%7Cd61ecb3b38b142d582c4efb2838b925c%7C1%7C0%7C636601293328785436&sdata=BzBxWsRJBeTCZlDe0GkyvNWx5hCLc1XrO84qbwXEOcQ%3D&reserved=0" target="_blank">https://github.com/Kitware/VTK/blob/master/Rendering/Volume/Testing/Cxx/TestGPURayCastMultiVolumeOverlapping.cxx#L229</a><u></u><u></u></p>
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Is this a technical limitation that would be very hard to overcome, or is it something simpler? I’m asking this because for this actor to be really used for volume rendering, shading would be necessary.<u></u><u></u></p>
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 <u></u><u></u></p>
<p class="MsoNormal" style="margin-left:.5in">
Thank you,<u></u><u></u></p>
<p class="MsoNormal" style="margin-left:.5in">
Csaba<u></u><u></u></p>
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<span style="font-size:12.0pt;font-family:"Arial",sans-serif;color:#0b4194">Sankhesh Jhaveri<u></u><u></u></span></h5>
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