Edit a network curve using the normal curve editing tools, while maintaining the intersections with the other curves in the network.
Normally when you edit a curve in the network, you run the risk of moving or reshaping the curve out of intersections with the rest of the network. To prevent this you can lock the curve intersections so editing tools won’t disrupt them.
To show the curve network toolbox, choose Surfaces > Curve Networks.
Lock a curve to maintain intersections
The curve network surfaces become invisible and the curve highlights.
To edit the curve network, unlock the locked curve by choosing the Lock intersection tool and clicking the locked curve.