What are Closing Points?

[MrCATIA]

jangminhyuck sent me a private message asking what is a closing point. How are closing points used when making a muti-section surface?

 

[MrCATIA]

When creating a surface or solid passing through a series of closed curves (with the Multi-Section Surface tool or the Multi-section Solid tool), the closing point is used to define the starting end of each section curve. This prevents the surface from being twisted.

Couplings can be used to add more sets of "closing points", adding additional control for how the surface transitions between each section curve.