<DIV><FONT color=#0000ff>&nbsp;hi all<BR>&nbsp;&nbsp;&nbsp;&nbsp; I am using vtkImageViewer2 to show arrows which generated by glyph class, and use vtkImageViewer2's GetRender()-&gt;addActor. But my </FONT></DIV>
<DIV><FONT color=#0000ff>programe always tells error "ERROR: In D:\VTK\VTK5.10.1</FONT></DIV>
<DIV><FONT color=#0000ff>\Filtering\vtkDemandDrivenPipeline.cxx, line 727<BR>vtkStreamingDemandDrivenPipeline (02C6E798): Input port 0 of algorithm </FONT></DIV>
<DIV><FONT color=#0000ff>vtkImageMapToWindowLevelColors(02C98638) has 0 connections but is not optional." . </FONT></DIV>
<DIV><FONT color=#0000ff>SO I hope get the helps from all of you, and thans to you for the advises in advance.</FONT></DIV><FONT color=#0000ff>
<DIV><BR>&nbsp;the main code is given as following:</DIV>
<DIV></FONT>&nbsp;</DIV>
<DIV><FONT color=#0000ff>vtkSmartPointer&lt;vtkImageViewer2&gt; m_pImageViewer;<BR>m_pImageViewer=vtkSmartPointer&lt;vtkImageViewer2&gt;::New();</FONT></DIV>
<DIV><FONT color=#0000ff>vtkSmartPointer&lt;vtkGlyph3D&gt; glyphFilter = vtkSmartPointer&lt;vtkGlyph3D&gt;::New();<BR>&nbsp;&nbsp;&nbsp;glyphFilter-&gt;SetSourceConnection(arrowSource-</FONT></DIV>
<DIV><FONT color=#0000ff>&gt;GetOutputPort());<BR>&nbsp;&nbsp;&nbsp;glyphFilter-&gt;OrientOn();&nbsp; <BR>&nbsp;&nbsp;&nbsp;glyphFilter-&gt;SetVectorModeToUseVector();<BR>&nbsp;&nbsp;&nbsp;glyphFilter-&gt;SetScaleModeToScaleByScalar(); <BR>&nbsp;&nbsp;&nbsp;glyphFilter-&gt;SetColorModeToColorByScalar(); <BR>&nbsp;&nbsp;&nbsp;glyphFilter-&gt;SetScaleFactor(5); </FONT></DIV>
<DIV><FONT color=#0000ff>glyphFilter-&gt;SetInputConnection(maskP-&gt;GetOutputPort());</FONT></DIV>
<DIV><FONT color=#0000ff>vtkSmartPointer&lt;vtkImageSliceMapper&gt; imageMapper = </FONT></DIV>
<DIV><FONT color=#0000ff>vtkSmartPointer&lt;vtkImageSliceMapper&gt;::New();<BR>imageMapper-&gt;SetInputConnection(vtkImporter-&gt;GetOutput()-&gt;GetProducerPort());</FONT></DIV>
<DIV><FONT color=#0000ff>vtkSmartPointer&lt;vtkLookupTable&gt; Lut=vtkSmartPointer&lt;vtkLookupTable&gt;::New();<BR>&nbsp;&nbsp;&nbsp;Lut-&gt;SetTableRange(-20,20);//(lo,hi);//(0,60);//&nbsp;</FONT></DIV>
<DIV><FONT color=#0000ff>&nbsp;&nbsp;&nbsp;Lut-&gt;SetHueRange(0,1);<BR>&nbsp;&nbsp;&nbsp;Lut-&gt;SetSaturationRange(1,1);<BR>&nbsp;&nbsp;&nbsp;Lut-&gt;SetValueRange(1,1);&nbsp; //////////<BR>&nbsp;&nbsp;&nbsp;Lut-&gt;SetAlpha(1);&nbsp;&nbsp;&nbsp;<BR>&nbsp;&nbsp;&nbsp;Lut-&gt;SetValueRange(-20,60);<BR>&nbsp;&nbsp;&nbsp;Lut-&gt;SetNumberOfTableValues(25600);<BR>&nbsp;&nbsp;&nbsp;Lut-&gt;SetRange(-20,60);<BR>&nbsp;&nbsp;&nbsp;Lut-&gt;SetVectorMode(vtkScalarsToColors::MAGNITUDE);<BR>&nbsp;&nbsp;&nbsp;Lut-&gt;Build(); </FONT></DIV>
<DIV><FONT color=#0000ff>vtkSmartPointer&lt;vtkPolyDataMapper2D&gt; vectorMapper = </FONT></DIV>
<DIV><FONT color=#0000ff>vtkSmartPointer&lt;vtkPolyDataMapper2D&gt;::New();<BR>&nbsp;&nbsp;&nbsp;vectorMapper-&gt;SetInputConnection(glyphFilter-</FONT></DIV>
<DIV><FONT color=#0000ff>&gt;GetOutputPort());<BR>&nbsp;&nbsp;&nbsp;vectorMapper-&gt;SetScalarRange(-20,20);//(lo,hi);<BR>&nbsp;&nbsp;&nbsp;vectorMapper-&gt;ScalarVisibilityOn();&nbsp; <BR>&nbsp;&nbsp;&nbsp;vectorMapper-&gt;SetLookupTable(Lut);<BR>&nbsp;&nbsp;&nbsp;vectorMapper-&gt;SetScalarModeToUsePointFieldData();<BR>&nbsp;&nbsp;&nbsp;vectorMapper-&gt;ColorByArrayComponent("ColorValue",3);<BR>&nbsp;&nbsp;&nbsp;vectorMapper-&gt;SetColorModeToMapScalars();</FONT></DIV>
<DIV><FONT color=#0000ff>vectorMapper-&gt;UseLookupTableScalarRangeOn();&nbsp;&nbsp;&nbsp;<BR>&nbsp;&nbsp;&nbsp;vectorMapper-&gt;ScalarVisibilityOn();</FONT></DIV>
<DIV><FONT color=#0000ff>&nbsp;&nbsp;&nbsp;vtkSmartPointer&lt;vtkActor2D&gt; vectorActor = </FONT></DIV>
<DIV><FONT color=#0000ff>vtkSmartPointer&lt;vtkActor2D&gt;::New();<BR>&nbsp;&nbsp;&nbsp;vectorActor-&gt;SetMapper(vectorMapper);</FONT></DIV>
<DIV><FONT color=#0000ff>m_pImageViewer-&gt;GetRenderer()-&gt;AddActor(vectorActor); </FONT></DIV>