Hello,<br><br>What will happen in the following case?<br><br>vtkSmartPointer&lt;vtkGeometryFilter&gt; gf = vtkSmartPointer&lt;vtkGeometryFilter&gt;::New();<br>gf-&gt;SetInput(unGrid);<br><br>vtkSmartPointer&lt;vtkThreshold&gt; thr = vtkSmartPointer&lt;vtkThreshold&gt;::New();<br>
thr-&gt;SetInputConnection(gf-&gt;GetOutputPort());<br><br>if( some_condition )<br>{<br>   thr-&gt;ThresholdByLower( some_value );<br>}<br><br>vtkSmartPointer&lt;vtkThreshold&gt; bthr = vtkSmartPointer&lt;vtkThreshold&gt;::New();<br>
bthr-&gt;SetInputConnection( thr-&gt;GetOutputPort() );<br>bthr-&gt;ThresholdByLower( BAD_VALUE );<br><br>vtkSmartPointer&lt;vtkDataSetSurfaceFilter&gt; surfFilter = vtkSmartPointer&lt;vtkDataSetSurfaceFilter&gt;::New();<br>
surfFilter-&gt;SetInputConnection( bthr-&gt;GetOutputPort() );<br>...<br>...<br><br>How will &#39;thr&#39; behave when &#39;some_condition&#39; is false? Will there be any thresholding? If so then what will be the threshold value? What values will be passed to &#39;bthr&#39;..??<br>
<br>I am asking this because, without<br><br>vtkSmartPointer&lt;vtkThreshold&gt; thr = vtkSmartPointer&lt;vtkThreshold&gt;::New();<br>
thr-&gt;SetInputConnection(gf-&gt;GetOutputPort());<br>
<br>
if( some_condition )<br>
{<br>
   thr-&gt;ThresholdByLower( some_value );<br>
}<br><br>part of code, previously it was displaying correct output. After inserting this code, I am getting blank output.. Output is to display filled contour for a grid.<br><br>Thanks<br><br>Regards<br>Rakesh Patil<br>