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<p class=MsoNormal><font size=2 color=maroon face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:maroon'>If your mesh is
typical, then probably most of the cells are of good quality, and there are a
handful of cells of bad quality. Thus, when volume rendering most of the
cells will be invisible and that handful of cells will have some opacity.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=maroon face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:maroon'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=maroon face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:maroon'>The probable
reason that you can see them in a small mesh and not a large one is that the
cells are spatially much smaller (with respect to the entire mesh) for the
large mesh. In correct volume rendering, a material of a constant density
will have smaller opacity the thinner it gets. Your cells are probably so
small that there is not enough accumulation to actually see them.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=maroon face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:maroon'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=maroon face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:maroon'>You can adjust
for the small scale of the cells by adjusting the “Scale” parameter
in the Color Scale Editor dialog box. That parameter is actually a unit
length specification for the opacity parameters given. Setting it to
about cell length divided by 10 should give you decent results. However,
an easier and probably more effective approach would be to bag the volume
rendering and use the threshold filter to extract the cells of interest (in
this case, the bad ones).<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=maroon face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:maroon'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=maroon face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:maroon'>-Ken<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=maroon face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:maroon'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
paraview-bounces@paraview.org [mailto:paraview-bounces@paraview.org] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Nathanael Inkson<br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, September 02, 2008
7:31 AM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">paraview@paraview.org</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> [Paraview] Strange
behaviour with large datasets</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Dear Paraview people,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>
I am working with Paraview with very large datasets (around 40Gb). I have
written a filter derived from MeshQuality which doesn’t seem to display
the returned data arrays correctly. I checked with the same mesh and the
MeshQuality filter. The same thing happens: I put the output on volume
rendering to look at the quality field and the whole dataset is invisible. I
have tried rescaling the range but to know avail. Is this a known problem?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Any advice? With smaller meshes the problem
disappears and the quality field is visible with volume rendering.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><b><font size=2 color=gray face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:gray;font-weight:bold'>Best
Regards<o:p></o:p></span></font></b></p>
<p class=MsoNormal><b><font size=2 color=gray face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:gray;font-weight:bold'> <o:p></o:p></span></font></b></p>
<p class=MsoNormal><b><font size=2 color=gray face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:gray;font-weight:bold'>Dr.
Nathanael Inkson,</span></font></b><b><font size=2 color=gray face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:gray;font-weight:bold'><o:p></o:p></span></font></b></p>
<p class=MsoNormal><b><font size=2 color=gray face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:gray;font-weight:bold'> <o:p></o:p></span></font></b></p>
<p class=MsoNormal><b><font size=2 color=gray face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:gray;font-weight:bold'>Computational
Fluid Dynamics Developer,</span></font></b><b><font size=2 color=gray
face=Verdana><span style='font-size:10.0pt;font-family:Verdana;color:gray;
font-weight:bold'><o:p></o:p></span></font></b></p>
<p class=MsoNormal><b><font size=2 color=gray face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:gray;font-weight:bold'>Digital
Flow Solutions,</span></font></b><b><font size=2 color=gray face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:gray;font-weight:bold'><o:p></o:p></span></font></b></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN-GB
style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><font
size=3 face="Times New Roman"><span lang=EN-GB style='font-size:12.0pt'> <img
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align=baseline border=0></span></font><strong><b><font size=1 color=gray
face=Verdana><span style='font-size:7.5pt;font-family:Verdana;color:gray'><o:p></o:p></span></font></b></strong></p>
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src="cid:image002.jpg@01C90CD1.517A0860" align=baseline border=0><strong><b><font
face=Verdana><span style='font-family:Verdana'><o:p></o:p></span></font></b></strong></span></font></b></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><strong><b><font
size=1 color=gray face=Verdana><span style='font-size:9.0pt;font-family:Verdana;
color:gray'>mob: + 44 7872010167</span></font></b></strong><strong><b><font
size=1 color=gray face=Verdana><span style='font-size:7.5pt;font-family:Verdana;
color:gray'><o:p></o:p></span></font></b></strong></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><strong><b><font
size=1 color=gray face=Verdana><span style='font-size:9.0pt;font-family:Verdana;
color:gray'>web: wirthresearch.com</span></font></b></strong><font
size=1><span lang=EN-GB style='font-size:9.0pt'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN-GB
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN-GB
style='font-size:12.0pt'><o:p> </o:p></span></font></p>
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