# Is it possible to Loft 1 Closed Curve to 2+ using only grasshopper?

I’m trying to loft dozens of single-closed-curves into two or more closed curves.

I’ve seen solutions where you need to manually fix it up on rhino, by patching and subDing.

It would save a lot of time and effort to be able to do this only on grasshopper. What would this approach look like?

Hi Francisco -

I suppose you’d just use the Loft component. Where are you getting stuck?
You might want to attach your .gh file with your curves internalized.
-wim

Here take a look at one of the examples!

Lofting Single to Multiple Curves.gh (12.6 KB)

You can see when lofting a single curve into two, the loft goes through both closed curves instead of splitting into a Y shape.

You’re going from a closed curve (that seems to touch at the intersection which isn’t ideal) to two open curves and grasshopper isn’t quite sure what you’re trying to achieve with the loft. Even just looking at it - how are you imagining the loft to look? Why not spit the single closed curve into two closed curves instead so they can branch off when encountering the curves in the middle?

Loft create a single surface.
There is no way your shape can be formed with only ONE surface.

I am afraid SubD is your best choice.

still 2 lofts, seams should be adjusted in a better way…
I don’t think it does exist an approach that will create the opening in the middle with a single loft, but I’m on this forum to be amazed

Lofting Single to Multiple Curves_inno.gh (23.3 KB)

Thanks for the input!
@ftzuk, the curves touch at the intersection because it is the ideal toolpath to 3D print a certain material.
As @11165 and @inno also suggested, it has to be lofted in 2 curves, or manually SubDed

I’m still curious to know if someone might find a way to do this through grasshopper, because this is a simplified version of a much larger and complex set of curves. It would save enormous amounts of time

actually grasshopper can do huge amount of subd operations.
you have 2 options:
1: create mesh and convert them to subd.
2: create subd from scratch using existed components.