Test for Perpendicular to Section Cut

[vfrontiers]

So I'm working on a 3d framing object for wood framing (and eventually converting to metal studs)...

It's been working great for 15 years, but now I want to add INSULATION to the object (more of a line graphic for sections than actual insulation)...

What I'd like the object to do is TEST the placement against the direction of the section cut so it only draws it if the object is perpendicular  (so all the other framing objects in the background don't have the FACE of INSULATION showing thru)...

I have done a similar thing testing the direction of the 3d camera, but can't find any way to do this for section elevation...

I have to make the insulation "squiggle" run the entire length of the framed wall, cuz I don't know where the section will be cut thru any object...

For now, I can make the elements MATERIAL "AIR" and go back to the GDL to turn off the LENGTH LINES via the STATUS CODES, but that seems like more work than testing perpendicular...

Let me know if you have any ideas...