To apply curves from a developed 2D pattern back to the 3D surface, follow these steps:

1. Create a developed surface from the 3D surface using UnrollSrf
2. Draw the 2D pattern on this surface to taste
3. Use CreateUVCrv (or in V3, under bonus tools CreateUVCrvOnSrf) to make UV curves from the developed surface including the added curves
4. ApplyCrv all of the curves created by CreateUVCrv back to the original surface

Download an example file