[Paraview] normals in programmable filter

[David E DeMarle]

Use vtkDataSetAttributes::Get/SetNormals() to access the normals.
Likewise use Get/SetTCoords() to access the texture coordinates.

od = self.GetOutput()
id = self.GetInput()
od.GetPointData().ShallowCopy(id.GetPointData())
innorm = od.GetPointData().GetNormals()
onorm = innorm.NewInstance()
onorm.DeepCopy(innorm)
onorm.SetName("NewNormals")
for x in range(0, onorm.GetNumberOfTuples()):
  a,b,c = onorm.GetTuple(x)
  print a,b,c
  a = -1*a
  b = -1*b
  c = -1*c
  onorm.SetTuple3(x, a,b,c)
od.GetPointData().SetNormals(onorm)


David E DeMarle
Kitware, Inc.
R&D Engineer
21 Corporate Drive
Clifton Park, NY 12065-8662
Phone: 518-881-4909


On Tue, Jun 26, 2012 at 2:09 PM, Kathleen Schwarz <kas382 at cornell.edu> wrote:
> Hello,
> I am trying to transform a surface using a programmable filter, and I am
> unable to get the output to use the normals.  Even the most basic filter:
>
>  output.PointData.append(inputs[0].PointData['Normals'], 'Normals')
>
> results in the mesh being copied but the normals not being used.  The
> normals appear as a Data Array, but are not used in rendering.  However,
> using the copy arrays option in the properties of the programmable filter
> lead to the normals being used correctly.
>
> What I would like to do is to apply an affine transformation on the point
> positions and normals (and visualize contours of a scalar field on a
> uniform, nonorthogonal parallelepiped grid), so I can't just use the copy
> arrays option.
>
> Thanks in advance!
> -Katie
>
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