vtkReverseSense destroys normals name
The vtkReverseSense
filter, when set to reverse normals, replaces the normals array with a new instance, with no array name (https://gitlab.kitware.com/vtk/vtk/blob/master/Filters/Core/vtkReverseSense.cxx#L103). For comparison, vtkPolyDataNormals
creates a new array, but it gives it the name "Normals"
(https://gitlab.kitware.com/vtk/vtk/blob/master/Filters/Core/vtkPolyDataNormals.cxx#L345).
This has undesired effects if, for example, the output of vtkReverseSense
is used together with some other data with unmangled normals in vtkAppendPolyData
, since apparently the latter discards arrays which have different names in the different inputs (in 8.2, but not in 8.1.2). See https://discourse.vtk.org/t/smooth-gouraud-shading-disappears-in-8-2