Loft: Twisted surfaces, how to untwist? (Connecting wrong verrticals)

Hello everyone, and thanks for taking the time to read this.
A am a beginner with Rhino/GH, coming from an engineering Background and SiemensNX and Ansys

Ultimately my model is uploaded to shapediver, where it can be adapted and the part file downloaded as STL for 3D-printing.

The problem: Loft sometimes connects the wrong points between two breps (already created using offset curve and Loft), resulting in an internally twisted Loft (Blue in picture). How can this problem be solved?


I guess it depends on the ordering of the Brep, but idk how i can access and change the ordering.

Bonus: Is there an easy way to create a solid from all enclosung surfaces?

Thank you

PS: First post, i tried to follow the guidelines. If there are things to be improved please let me know.

Twisted_Loft_reduced.gh (34.1 KB)

It’s not always straightforward for the Loft operation to find the right way to connect two curves. Typically, when you use the Rhino command, there is a manual step requiring you to align the seams before the loft is performed.

I would recommend to loft the segments of curves individually before joining them all together. I adapted your definition according this strategy (it’s a bit messy but you’ll get the idea).

Twisted_Loft_reduced.gh (51.3 KB)

1 Like

Yes Loft in grasshopper is a little bit tricky.
What works for me pretty well is to adjust a seam of a curve by finding closest point on the curve.
It works on the case to case basis so you need to develop logic where to place those points so it works for you.

Hope this help


Twisted_Loft_reduced.gh (36.8 KB)

1 Like

Hello Mathieu and Lukasz,

Thank you both for taking the time to modify the GH script. I’ve implemented your solutions and both achieve the wanted result!

People like you make such forums extremely helpful, keep it uo!