[Hgholami]

Hello,
I have a curved beam in 2D as stl file, I want to send information of each cell of upper and bottom of beam to center line cell. but as the each center point of cell have location as Cartesian coordinate x,y,z, I don't know how can I collect relative point of upper side to bottom side.
as illustrated in figure.
beam.jpg
each red point of bottom side have relative red point in upper, for curved beam, how can I code to recognize each relative points together.