eror c2027: use of undefined type &#39; vtk porperty &#39;. What is the mean of this error? I compile this code :<br><br><div id="textboxstyle">
        <p align="left">#include &quot;vtkSphereSource.h&quot;<br>  #include &quot;vtkPolyDataMapper.h&quot;  <br>#include &quot;vtkActor.h&quot;  <br>#include &quot;vtkRenderWindow.h&quot;  <br>#include &quot;vtkRenderer.h&quot;  <br>
#include &quot;vtkRenderWindowInteractor.h&quot;    </p>
        <p align="left">void main ()  <br>{      </p>
        <p align="left">   // create sphere geometry   <br>   vtkSphereSource *sphere = vtkSphereSource::New();  <br>    sphere-&gt;SetRadius(1.0);   <br>   sphere-&gt;SetThetaResolution(18);   <br>   sphere-&gt;SetPhiResolution(18);  </p>

        <p align="left">            // map to graphics library    <br>  vtkPolyDataMapper *map = vtkPolyDataMapper::New();   <br>   map-&gt;SetInput(sphere-&gt;GetOutput());      </p>
        <p align="left">  // actor coordinates geometry, properties, transformation  <br>  vtkActor *aSphere = vtkActor::New();    <br>  aSphere-&gt;SetMapper(map);    <br>  aSphere-&gt;GetProperty()-&gt;SetColor(0,0,1); // sphere color blue      </p>

        <p align="left">  // a renderer and render window    <br>  vtkRenderer *ren1 = vtkRenderer::New();    <br>  vtkRenderWindow *renWin = vtkRenderWindow::New();    <br>  renWin-&gt;AddRenderer(ren1);      </p>
        <p align="left">  // an interactor    <br>  vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();    <br>  iren-&gt;SetRenderWindow(renWin);      </p>
        <p align="left">  // add the actor to the scene   <br>   ren1-&gt;AddActor(aSphere);   <br>  ren1-&gt;SetBackground(1,1,1); // Background color white </p>
        <p align="left">  // render an image (lights and cameras are created automatically) <br>
            renWin-&gt;Render();      </p>
        <p align="left">  // begin mouse interaction <br>
              iren-&gt;Start();  <br>
          }</p>
        </div>moreover    ;  error c2227 :  left of&#39;-&gt; setcolor&#39; must point to class/struct/union/generic type<br><br>what is the reason of these two errors?  <br><br><br>salih halil sonmez <a href="mailto:salihhalilsonmez@gmail.com">salihhalilsonmez@gmail.com</a><br>