[vtkusers] FrontfaceCullingOn() treats two vtkactors differently?

[Harriet King, Plastic Flow]

Thanks for any help you can provide.

I’m a vtk newbie, updating existing software that uses two vtkActors
displaying mesh tubes.  We’re using FrontfaceCullingOn() and one mesh
tube shows mesh on the far side of the tube when you look down the
tube shape and one does not show mesh on the far side but treats it
like the whole far side of the tube is undisplayed.  We want to see
the mesh on the far side when you look down the tube.  

We have two vtkactors named “domain” and “interface”, both created
the same way, with the same qualities, but pointing to different VTK
files with their vtkDatasetReader.    Both files are “DATASET
UNSTRUCTURED_GRID” but “CELL_TYPES” is 5 (=triangle, thus
2-dimensional) for interface and “CELL_TYPES”  is 10 (=tetrahedron,
thus 3-dimensional) for domain.  The “CELLS” for domain correctly
have 4 nodes and for interface have 3 nodes.  Both domain and
interface display and behave correctly except for
FrontfaceCullingOn().

Does FrontfaceCullingOn() recognize that interface is 2-d?  How can
we correct to see the mesh down the tube shape with interface?

THank you!