Access to intermediate points `vtkContourRepresentation`

Development
1

I working with the family of vtkContourWidget specifically to define trajectories on surfaces of organs. I decided to inherit the representation to expose the intermediate points and create an observer which defines orientations along the contour.

image
image604×664 29.1 KB

Is there a reason why it is not possible to GetIntermediatePointsAsPolyData()? Would it be an idea to add such a method?

Thanks in advance
Jens

2

It is as simple as adding this function to vtkOrientedGlyphContourRepresentation. Would this be okay to add?

//------------------------------------------------------------------------------
void vtkOrientedGlyphContourRepresentationEx::GetIntermediatePolyData(vtkPolyData* poly)
{
  poly->Initialize();
  int count = this->GetNumberOfNodes();

  if (count == 0)
  {
    return;
  }

  vtkNew<vtkPoints> points;
  vtkNew<vtkCellArray> lines;

  int i, j;
  vtkIdType index = 0;

  count = 0;
  for (i = 0; i < this->GetNumberOfNodes(); i++)
  {
    count += this->GetNumberOfIntermediatePoints(i);
  }

  points->SetNumberOfPoints(count);

  vtkIdType numLines;

  if (this->ClosedLoop && count > 0)
  {
    numLines = count + 1;
  }
  else
  {
    numLines = count;
  }

  if (numLines > 0)
  {
    vtkIdType* lineIndices = new vtkIdType[numLines];

    double pos[3];
    for (i = 0; i < this->GetNumberOfNodes(); i++)
    {
      int numIntermediatePoints = this->GetNumberOfIntermediatePoints(i);

      for (j = 0; j < numIntermediatePoints; j++)
      {
        Superclass::GetIntermediatePointWorldPosition(i, j, pos);
        points->InsertPoint(index, pos);
        if (index < numLines)
        {
          lineIndices[index] = index;
        }
        index++;
      }
    }

    if (Superclass::ClosedLoop)
    {
      lineIndices[index] = 0;
    }

    lines->InsertNextCell(numLines, lineIndices);
    delete[] lineIndices;
  }

  poly->SetPoints(points);
  poly->SetLines(lines);
}