[Paraview] Incorrect shading results in ParaViewWeb Local(VGL) mode

[Xue Junjie]

It seems the Local(VGL) rendering mode in ParaViewWeb has issues with 
some model files.

How to reproduce the issue:
open the visualiser, selecte the data file: 'can.ext2'.
Under 'Remote mode': all is ok, no issue
Under 'Local(VGL) mode': if the model is zoomed out to a certain 
distance, some faces on the model is shaded black.

I guees this is caused by the rendering mechanism differences between 
Paraview and ParaViewWeb . This issue exists in both paraview4.3 & 4.4, 
anyone knows how to solve it? or any other solutions the get correct 
rendering results in Local(VGL) mode? Thanks in advance!

Junjie Xue
Beihang University