Hi Bartosh, so just to clarify, those example files you posted previously were those saved from a Modo Catmull-Rom spline curve or were they exports of 2-vertex polylines?

What happens if you try to export a single line with just 2 vertices in it to .obj ?

Maybe it's possible to make a script that parses these particular .obj files in a different way than the regular .obj converter but I'm not sure how it could identify an open curve like in your first screenshot versus a closed loop. An n-gon in an .obj file is implicitly a closed thing, there isn't any way for it to be labeled that it's supposed to be treated as an open curve instead of a closed polygon. And then the results of making a NURBS control point curve through those points is going to look different than the Modo Catmull-Rom spline curve.

- Michael