It’s been a long time since I used OpenNest but I don’t think that’s true. Converting to polygons may affect how they overlap but it works fine for me without doing that. Other settings like ‘Iterations’, ‘Rotations’ and ‘Seed’ seem to have more effect on the results, though they can increase run time.
Note that only one sheet is supplied, OpenNest makes as many copies (sheets) as necessary. Curves are internalized, no need for Rhino file.
Nesting_2022Sep22aa.gh (20.7 KB)
