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    Hi David,<br>
    <br>
    Haha, wow, I was totally not understanding this method! It does
    make  sense now. Thank you :)<br>
    <br>
    One last question, just to be sure, what does the <tt>y</tt> and <tt>z</tt>
    parameters become? Here's the complete method, for clarity and for
    the next vtk users:<br>
    <small><tt>bool GetNext(int& x1, int& x2, int& y,
        int& z)</tt><tt><br>
      </tt><tt>{</tt><tt><br>
      </tt><tt>  int maxX, maxY, maxZ, dump;</tt><tt><br>
      </tt><tt>  m_ImageStencilData->GetExtent(dump, maxX, dump,
        maxY, dump, maxZ);</tt><tt><br>
        <br>
      </tt><tt>  bool gotExtent = false;</tt><tt><br>
      </tt><tt>  while (!gotExtent) </tt><tt><br>
      </tt><tt>  {</tt><tt><br>
      </tt><tt>    gotExtent = m_ImageStencilData->GetNextExtent(</tt><tt><br>
      </tt><tt>      x1, x2, 0, maxX, m_Y, m_Z, m_Iter) > 0;</tt><tt><br>
      </tt><tt><br>
      </tt><tt>    if (!gotExtent) { m_Iter = 0; ++m_Y;  }</tt><tt><br>
      </tt><tt>    if (m_Y > maxY) { m_Y = 0; ++m_Z; }</tt><tt><br>
      </tt><tt>    if (m_Z > maxZ) { m_Z = 0; return false; }</tt><tt><br>
      </tt><tt>  }</tt><tt><br>
      </tt><tt><br>
      </tt><tt>  y = m_Y; z = m_Z;</tt><tt> // <font color="#ff0000"><b>y
            and z ???</b></font><br>
      </tt><tt>  return true;</tt><tt><br>
      </tt><tt>}</tt></small><br>
    <br>
    Nil<br>
    <br>
    <div class="moz-cite-prefix">Le 2015-04-30 12:55, David Gobbi a
      écrit :<br>
    </div>
    <blockquote
cite="mid:CANwS1=HATECTK8ue4Ez3K-fiSj-k7AjSi6=5QWJ3fxP8gH1FNQ@mail.gmail.com"
      type="cite">
      <div dir="ltr">
        <div class="gmail_extra">
          <div class="gmail_quote">On Thu, Apr 30, 2015 at 9:53 AM,
            David Gobbi <span dir="ltr"><<a moz-do-not-send="true"
                href="mailto:david.gobbi@gmail.com" target="_blank">david.gobbi@gmail.com</a>></span>
            wrote:<br>
            <blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
              <div dir="ltr">
                <div>Hi Nil,</div>
                <div><br>
                </div>
                <div>I wrote a stencil iterator that provides the x, y,
                  and z indices (not in VTK yet).  It still requires an
                  image to iterate over, but it might be worth a glance:</div>
                <a moz-do-not-send="true"
href="https://github.com/dgobbi/AIRS/blob/master/ImageSegmentation/vtkImageRegionIterator.h"
                  target="_blank">https://github.com/dgobbi/AIRS/blob/master/ImageSegmentation/vtkImageRegionIterator.h</a><br>
                <div class="gmail_extra"><br>
                </div>
                <div class="gmail_extra">In order for your GetNext()
                  function to work as an iterator function, it should
                  not have any loops, just conditionals:</div>
                <div class="gmail_extra"><br>
                </div>
                <div class="gmail_extra">if ->GetNextExtent() returns
                  zero, it should reset m_Iter to zero and increment m_Y<br>
                </div>
                <div class="gmail_extra">if m_Y > maxY, it should
                  reset m_Y to zero and increment m_Z</div>
                <div class="gmail_extra">if m_Z > maxZ, it should
                  reset m_Z to zero and return false</div>
              </div>
            </blockquote>
            <div><br>
            </div>
            <div>I realized that it isn't quite as simple as what I
              wrote.  Everything has to be in a loop, because it has to
              keep trying until it gets a valid extent:</div>
            <div><br>
            </div>
            <div>  bool gotExtent = false;</div>
            <div>  while (!gotExtent)</div>
            <div>    {</div>
            <div>    gotExtent = m_ImageStencilData->GetNextExtent()</div>
            <div>    if gotExtent is zero, it should reset m_Iter to
              zero and increment m_Y</div>
            <div>
              <div class="gmail_extra">    if m_Y > maxY, it should
                reset m_Y to zero and increment m_Z</div>
              <div class="gmail_extra">    if m_Z > maxZ, it should
                reset m_Z to zero and return false</div>
            </div>
            <div>    }</div>
            <div><br>
            </div>
            <div>No guarantees, of course, since it's completely
              untested pseudocode.</div>
            <div><br>
            </div>
            <div> - David</div>
            <div><br>
            </div>
            <div><br>
            </div>
            <blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
              <div dir="ltr">
                <div>
                  <div class="h5">
                    <div class="gmail_extra">
                      <div class="gmail_quote">On Thu, Apr 30, 2015 at
                        8:54 AM, Nil Goyette <span dir="ltr"><<a
                            moz-do-not-send="true"
                            href="mailto:nil.goyette@imeka.ca"
                            target="_blank">nil.goyette@imeka.ca</a>></span>
                        wrote:<br>
                        <blockquote class="gmail_quote"
                          style="margin:0px 0px 0px
0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
                          <div bgcolor="#FFFFFF" text="#000000"> Hi all,<br>
                            <br>
                            I'm  using <tt>vtkPolyDataToImageStencil</tt>
                            to get all voxels index inside of a surface.
                            If I understand correctly, I have only two
                            choices here:<br>
                            - <tt>vtkImageStencil</tt> to create a new
                            image<br>
                            - <tt>vtkImageStencilIterator</tt> to
                            iterate on the values (of another image)<br>
                            The problem is, I have a different goal in
                            mind. I need the index of all voxels inside
                            a surface.<br>
                            <br>
                            I read the <tt>vtkPolyDataToImageStencil</tt>
                            code and tried to create my own "iterator"
                            but there's probably something I don't
                            understand; <tt>GetNextExtent</tt> always
                            return 0.<br>
                            <small><tt>bool GetNext(int& x1,
                                int& x2, int& y, int& z)</tt><tt><br>
                              </tt><tt>{</tt><tt><br>
                                  // m_Y, m_Z and m_Iter == 0</tt></small><small><tt><br>
                                  int maxX, maxY, maxZ, dump;</tt><tt><br>
                              </tt><tt> 
                                m_ImageStencilData->GetExtent(dump,
                                maxX, dump, maxY, dump, maxZ);</tt><tt><br>
                              </tt><tt>  maxX *= 2; maxY *= 2; maxZ *=
                                2;</tt><tt><br>
                              </tt><tt><br>
                              </tt><tt>  for ( ; m_Z <= maxZ; ++m_Z)</tt><tt><br>
                              </tt><tt>  {</tt><tt><br>
                              </tt><tt>    for ( ; m_Y <= maxY;
                                ++m_Y)</tt><tt><br>
                              </tt><tt>    {</tt><tt><br>
                              </tt><tt>      if
                                (m_ImageStencilData->GetNextExtent(x1,
                                x2, 0, maxX, m_Y, m_Z, m_Iter))</tt><tt><br>
                              </tt><tt>      {</tt><tt><br>
                              </tt><tt>        y = m_Y; z = m_Z;</tt><tt><br>
                              </tt><tt>        return true;</tt><tt><br>
                              </tt><tt>      }</tt><tt><br>
                              </tt><tt>    }</tt><tt><br>
                              </tt><tt>  }</tt><tt><br>
                              </tt><tt>  return false;</tt><tt><br>
                              </tt><tt>}</tt></small><br>
                            <br>
                            Is there a way to access all inside-voxels
                            hidden in the <tt>vtkPolyDataToImageStencil</tt>?
                            By index or by index range, it's not
                            important. I just want to know to access
                            them without useless work (like creating an
                            image) because it's gonna be called often;
                            it needs to be fast. Thank you for your
                            time.<span><font color="#888888"><br>
                                <br>
                                Nil<br>
                              </font></span></div>
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