how does "Orientationextractor" work?

Hi All,

 

 

I have a building and I wanna check two things:

 

1) if the surface normal for all surfaces are pointing outwards,

 

2) if the ordering of the points for all polygons(surfaces) of a building are the same

 

 

First I was thinking the orientationextractor would work. But now I am confused that how RHR has been defined in FME and how is it applied.

 

 

here is one example which is in the opposite of the help definition for orientationextractor:

 

So here you see the order of the points is in clockwise and orientation is RHR.

 

I changed manually the ordering into counterclockwise to see what happens and it is still RHR.

 

So how does it exactly work?

 

how can check the ordering and normal vector in this way?

 

Thank you in advance

 

Mani