That is probably an oversight. Try changing the vtkSelectVisiblePoints::RequestData to do an early check for empty input dataset and make it produce an empty output dataset and return 1. <div><br></div><div>If that change doesn't break any regression tests on your machine please send the patch to the list and we'll push it to the repository.<div>
<br clear="all">David E DeMarle<br>Kitware, Inc.<br>R&D Engineer<br>28 Corporate Drive<br>Clifton Park, NY 12065-8662<br>Phone: 518-371-3971 x109<br>
<br><br><div class="gmail_quote">2011/6/4 Andreas Buykx <span dir="ltr"><<a href="mailto:A.Buykx@tnodiana.com">A.Buykx@tnodiana.com</a>></span><br><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"><span lang="EN-US">Hi all,</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">I have a pipeline in my application that should display the ids of visible points, using a.o. the vtkSelectVisiblePoints filter. The input to this filter is a – possibly empty - selection of the original data set.
</span></p>
<p class="MsoNormal"><span lang="EN-US">When the set is in fact empty, I get a lot of the following errors:</span></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-US" style="font-size:9.0pt;font-family:"Courier New"">ERROR: In <path-deleted>/VTK/src/Filtering/vtkExecutive.cxx, line 753</span></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-US" style="font-size:9.0pt;font-family:"Courier New"">vtkStreamingDemandDrivenPipeline (0x32b8700): Algorithm vtkSelectVisiblePoints(0x3168ea0) returned failure for request: vtkInformation (0x3340180)</span></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-US" style="font-size:9.0pt;font-family:"Courier New""> Debug: Off</span></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-US" style="font-size:9.0pt;font-family:"Courier New""> Modified Time: 23448</span></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-US" style="font-size:9.0pt;font-family:"Courier New""> Reference Count: 1</span></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-US" style="font-size:9.0pt;font-family:"Courier New""> Registered Events: (none)</span></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-US" style="font-size:9.0pt;font-family:"Courier New""> Request: REQUEST_DATA</span></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-US" style="font-size:9.0pt;font-family:"Courier New""> FROM_OUTPUT_PORT: 0</span></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-US" style="font-size:9.0pt;font-family:"Courier New""> FORWARD_DIRECTION: 0</span></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-US" style="font-size:9.0pt;font-family:"Courier New""> ALGORITHM_AFTER_FORWARD: 1</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">I looked in the code and found that this filter returns a 0 from RequestData if the input dataset is empty. In my situation an empty input dataset is a valid input condition and I’d like to prevent all these errors. What
are my options?</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">Thanks for your help!</span></p>
<p class="MsoNormal" style="text-autospace:none"><b><span lang="EN-US" style="font-size:10.0pt;color:black">Andreas Buykx</span></b></p>
<p class="MsoNormal" style="text-autospace:none"><span lang="EN-US" style="font-size:10.0pt;color:black">Senior Software Engineer</span></p>
<p class="MsoNormal" style="text-autospace:none"><span lang="EN-US" style="font-size:10.0pt;color:black"> </span></p>
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