[vtkusers] vtkTransformFilter and precisions

[Murat Aydın]

Hi,

I noticed something. There is setDataTypeToDouble() method in vtkPoints. The reason of precision loss may be that default dataType of vtkPoints is float. How can i set default dataType of vtkUnstructured grid to double? How can i change dataType of points? Thanks.

Kind Regards,

murat
  ----- Original Message ----- 
  From: Murat Aydın 
  To: vtkusers at vtk.org 
  Sent: Wednesday, February 03, 2010 12:01 PM
  Subject: [vtkusers] vtkTransformFilter and precisions


  Hi,

  Precisions change after executing vtkTransformFilter. My code is the following:

  vtk.vtkTransform transformRotate3 = new vtk.vtkTransform();
  transformRotate3.RotateWXYZ(45.0, 1, 0, 0);
  vtk.vtkTransformFilter transformFilterRotate3 = new vtk.vtkTransformFilter();
  transformFilterRotate3.SetTransform(transformRotate3);
  transformFilterRotate3.SetInputConnection(transformFilterRotate2.GetOutputPort());

  transformFilterRotate2 is another transformFilter.

  Distance between points[0] and points[4] is 20.0 in  transformFilterRotate2.GetUnstructuredGridOutput()
  After executing  transformFilterRotate3
  distance between points[0] and points[4] is 20.032103138407294

  I am getting points by the following code:

  transformFilterRotate2.GetUnstructuredGridOutput().GetPoint(0)
  transformFilterRotate2.GetUnstructuredGridOutput().GetPoint(4)

  transformFilterRotate3.GetUnstructuredGridOutput().GetPoint(0)
  transformFilterRotate3.GetUnstructuredGridOutput().GetPoint(4)


  why the distance changed from 20.0 to 20.032103138407294? How can i prevent this?

  Kind Regards,

  murat aydin


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