invalid array name

Support
1

I write
calculator = vtk.vtkArrayCalculator() calculator.SetInputConnection(cellToPoint.GetOutputPort()) calculator.SetAttributeType(vtk.vtkDataObject.POINT ) print(calculator.GetNumberOfScalarArrays()) calculator.AddScalarArrayName("VelocityX",0)
and I think it’s no problem,but the command windows get me a error message invalid array name "VelocityX",I do not konw where is wrong ,who can help me.Thanks.By the way,the cellToPoint.GetOutputPort() output type is vtkPolyData

2

Hi, Hao,

You have to set the name of the scalar array when you create it:

   vtkSmartPointer<vtkFloatArray> values = vtkSmartPointer<vtkFloatArray>::New();
   values->SetName("VelocityX");

kind regards,

Paulo

3

Also, depending on how your code structure is designed, your calculator object is going out of scope, thereby destroying your “Velocity0” scalar field before the VTK framework has a chance to use it.