Centre Lines: 3d Line vs Symmetry Plane

[[Ol...]]

Hi all,

I see that a lot of people use Symmetry Planes to construct centre lines on their programs.
Is there a reason that this a better method than creating a 3d line?

Thank you,

Ollie.
THORLABS

[[Ro...]]

Symmetry Planes are features of size, so you can report the size of the feature and also use it to calculate material condition.

[[To...]]

The 3d line is not better or worse than a Symmetry Plane. However, a line is a 2d feature which might be fine for narrow planar surfaces but when applied to wider planar surfaces, does not reflect angular issues in the perpendicular direction.