No subject

[Wei.Shao at waii.com]

Hi folks:

In one of my application, I want to modify the point positions in a
vtkPolyData. I found out the following two piece of codes gave me the same
effect. In Code A: I extracted the vtkPoints from the vtkPolyData and reset
the value of a given point through vtkPoints. In Code B: I copy the
vtkPoints of vtkPolyData to a new vtkPoints, and set the new vtkPoints to
the vtkPolyData. Code A looks much simpler than Code B.

However the vtkPointPicker is not working any more when I used the Code A.
This really puzzled me. Please tell me the reason If someone know why.

Wei Shao


Code A:
              vtkPolyData *m_pSelectedObject;
              .............................
     vtkPoints  *pPts =  m_pSelectedObject->GetPoints();

     float *p;
               ..........  // get p
               pPts->InsertPoint(0, p);
              m_pSelectedObject->Modified();


Code B:
     vtkPoints  *pPts =  m_pSelectedObject->GetPoints();


     float *p;

     vtkPoints *pNewPts = vtkPoints::New();
     int numPts = pPts->GetNumberOfPoints();
     pNewPts->Allocate(numPts, numPts);
     for(int i =0 ; i< numPts; i++)
     {
               p=pPts->GetPoint(i);
               if(i == 0)
               {
                    p = //get p from some where
               }
               pNewPts->InsertNextPoint(p);
     }

     m_pSelectedObject->SetPoints(pNewPts);
     m_pSelectedObject->Modified();
     pNewPts->Delete();








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