<pre><font style="font-family: tahoma,sans-serif;" size="2">Hello,<br><br>vtkPoints *pnts = vtkPoints::New();<br>pnts-&gt;SetNumberOfPoints(num);<br><br>vtkDoubleArray *scalar = vtkDoubleArray::New();<br>scalar-&gt;SetNumberOfTuples(num);<br>
<br>vtkCellArray *pVertex = vtkCellArray::New();<br><br>for (vtkIdType i = 0; i &lt; num; i++)<br>{<br>   readFile &gt;&gt; xval &gt;&gt; yval &gt;&gt; zval;<br>   pnts-&gt;InsertPoint(i, xval, yval, 0);<br>   scalar-&gt;InsertTuple1(i, zval);<br>
   pVertex-&gt;InsertNextCell(1, &amp;i);<br>}<br><br>vtkPolyData *pd = vtkPolyData::New();<br>pd-&gt;SetPoints(pnts);<br>pd-&gt;SetVerts(pVertex);<br>pd-&gt;GetPointData()-&gt;SetScalars(scalar);<br><br>vtkDelaunay2D *del = vtkDelaunay2D::New();<br>
del-&gt;SetInput(pd);<br>del-&gt;SetTolerance(0.00001);<br>del-&gt;Update();<br><br>vtkPolyDataMapper *mapp = vtkPolyDataMapper::New();<br>mapp-&gt;SetInputConnection( del-&gt;GetOutputPort() );<br>mapp-&gt;ScalarVisibilityOn();<br>
<br>vtkActor *actor = vtkActor::New();<br>actor-&gt;SetMapper(mapp);<br>actor-&gt;GetProperty()-&gt;SetColor(1, 0, 0);<br>actor-&gt;GetProperty()-&gt;SetPointSize(3);<br><br>renderer-&gt;AddActor(actor);<br><br>After adding actor to the renderer, suppose I do some changes in the scalar array, and say modified, I observe that delaunay object is also updated and again triangulation takes place.<br>
<br>Why is this so? <br>;</font><br></pre>