In fact it's appear that the internal first curve is also possible with a simple nurb 😄
Just click middle of segment A, click Apex AB, Click middle of segment B, click Apex BC etc...
Maybe special Bezier curve of Fredo6 can be near the solution 😄
💡 LightUp 7.1 | SketchUp's only real-time renderer that uses object-based rendering
Download Trial
T