Setup:

• Mac OS X El Capitan 10.11.5
• Python 2.7.11 (installed through homebrew)
• VTK (installed through homebrew but using the head of master with the vtkNoPythonLink branch merged in. this is due to this bug)
• Mayavi 4.4.4 (installed through pip)

I then ran the Protein example

Expected:
I would expect to see tubes between the proteins

Actual
I did not see tubes between proteins