Arbitrary vtk object to PolyDataMapper

Hi,

I'm very new to Mayavi and confused about various objects and their structure.
Documentation and docstrings is great, thanks. Without it I couldn't even start

I want to convert object to PolyDataMapper because I want to get color lookup table information which seems
lost when saving object as OBJ (Wavefront)

For example I made tvtk.ImageData object, but simply passing it to tvtk.PolyDataMapper as argument in a
hope to get converted object is not possible: "AttributeError: 'ImageData' object has no attribute 'IsA'"
So I guess I'm doing it wrong, and thought to ask for help

Thanks

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