What's the math behind "aspect ratio"?

I’m wondering what’s the math behind aspect ratio.
For Example:
_ExtractMeshFacesByASpectRatio
If I choose to pick the aspect ratio from a face I get a number.
How is this number computed?
I would expect some correlation between the edges or inner/outer circle.

Thank you!

1 Like

As mentioned here it’s based on Stan Melax’s polygon reduction:

cost\left(u,v\right) = \Vert{u-v}\Vert \times \underset{f\in{Tu}}{max} \left\{\underset{n\in{Tuv}}{min}\left\{\frac{1- f.normal\bullet n.normal}{2}\right\}\right\}

where Tu is the set of triangles that contain u and Tuv is the set of triangles that contain
both u and v.

Thank you for the quick feedback!