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<TITLE>Bug found in vtkVoxelContourToSurfaceFilter.cxx</TITLE>
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<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">It is in the member function</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">of class</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">vtkVoxelContourToSurfaceFilt</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">er.</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> When pushing the distance along X or Y</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> directions</FONT><FONT FACE="Calibri">,</FONT> <FONT FACE="Calibri">forward and backward</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">pushing</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"></FONT> <FONT FACE="Calibri">are both require</FONT><FONT FACE="Calibri">d.</FONT><FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">While in the backward pushing, (line 420-</FONT><FONT FACE="Calibri">430 for X direction, line</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> 460-470 for Y direction), the pointer</FONT> <FONT FACE="Calibri">"</FONT><FONT FACE="Calibri">vptr</FONT><FONT FACE="Calibri">" is not updated</FONT><FONT FACE="Calibri">. For X direction</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">, "vptr" should be updated with</FONT> <FONT FACE="Calibri">"</FONT><FONT FACE="Calibri">vptr--</FONT><FONT FACE="Calibri">" right after line 429, while for Y direction, "vptr" should be u</FONT><FONT FACE="Calibri">pdated with "</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">vptr-=gridSize[0]" right after line 469.</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> With this bug, the resulting surface has a lot of "holes"</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">when rendered for visualization. </FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">A</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> question</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">, can we push the distance along Z direction, just like</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">what</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">we did</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">a</FONT><FONT FACE="Calibri">long</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> X and Y direction</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">s</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">?</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">What if we compare</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> the surface generation method</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> in vtkVoxelContourToSurfaceFilter with the method</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">by converting the 2d contours to a 3d binary image and then</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">using itkAntiAlias</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">BinaryImageFilter and</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> vtkContourFilter?</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">Which one has more advantages</FONT><FONT FACE="Calibri">?</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> </SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">Thanks,</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">Jinzhong</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">_____</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">Jinzhong Yang, Ph.D.</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">jinzhong.yang@ieee.org</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">(713) 792-2814</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
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