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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Utkarsh,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Unfortunately, the STL that produced the issue is confidential and also quite large, so I am unsure how to go about producing something equivalent.
Let me know what you find after looking at the reader and I will try to find something appropriate. To be honest, the reasoning is speculative, but it is clear that the STL reader has some drawbacks. At the very least we would be happy to test any alterations
you might come up with on the original input.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Not merging the points is a reasonable work-around, but you will lose some utility (feature detection). I think it should be relatively easy to create
or port an existing algorithm that is a bit more efficient (of course these kind of assumptions tend to be wrong, but anyway!).<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Eugene<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Utkarsh Ayachit [mailto:utkarsh.ayachit@kitware.com]
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<b>Sent:</b> 05 July 2016 17:05<br>
<b>To:</b> Eugene de Villiers <e.devilliers@engys.com><br>
<b>Cc:</b> paraview@paraview.org<br>
<b>Subject:</b> Re: [Paraview] Suggestion for STL import<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Eugene,<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">I am pretty sure the community will be interested in this! While I'll need to look into the reader to understand, to get things going, do you have a sample dataset to demonstrate the issue?<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Utkarsh <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">On Tue, Jul 5, 2016 at 10:28 AM, Eugene de Villiers <<a href="mailto:e.devilliers@engys.com" target="_blank">e.devilliers@engys.com</a>> wrote:<o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Hi,</span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"> </span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">When importing STL format geometry or similar, where connectivity information is not implicit in the data structure, it appears that the connectivity is reconstructed via an octree
search. This is very inefficient when surfaces with large differences in edge length are imported – we have had a recent case where an STL took 45mins to load. If the same input geometry is converted to OBJ format via an external tool, the load time reduces
to minutes.</span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"> </span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">A generally more efficient method is to calculate the distance of each point from a location outside the point cloud bounding box and then to bubble-sort the resulting list. Unless
you are dealing with a pathological case your local search neighbourhood of identical distance points will be small and the algorithm very fast. More complex, multi-origin algorithms are also possible to counter pathological instances.</span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"> </span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">I can provide more details and sample code if you are interested.</span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"> </span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Best regards,</span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"> </span><o:p></o:p></p>
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<b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Eugene de Villiers</span></b><o:p></o:p></p>
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<i><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Managing Director</span></i><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><a href="mailto:e.devilliers@engys.com" target="_blank">e.devilliers@engys.com</a></span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Mob:
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<span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Tel:
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