[vtkusers] normal of a point or cell

[Chris Tsui]

Dear All,

I posted this question few days ago...  getting no reply..  I guess this 
is kind of stupid that no one would bother to answer..  but I am still 
struggling with this problem..  anyways.. here's my question again :

- I would like to get the normal whenever I click on the surface of the 
mesh I have..  I can get the cell id or the world coordinates without 
problem..  what I am struggling with is how to retrieve the normal of a 
specific cell??  any idea?? 

your help would be greatly appreciated.

Regards,

Chris.