TWEEN CURVE on a complex geometry

Have a problem with creating tween curves between complex lines.

01.3dm (4.9 MB)

a tween curve is a curve between 2 curves. Do you want all tween curves between all pairs of curves ?
More than 6000 curves in your shape, have you an idea of the number of pairs it represent?

Can you draw what you want ?

You are perhaps seeking for Medial Axis or Offset ?