Sweep 2 problem

Hi, i’m trying to build a simple surface between with a sweep2 operation between two helix curves, but im encountering an issue with the resulting surface as displayed below. My guess is that the length of the two curves varies, which causes issues.

I can easily build the a shape with Sweep1; using 1 of the rail curves and 1 profile curve. The reason for using Sweep2 is in order to be able to vary the profile/depth of the curve at specific points along the curves.

*i have also tried using loft, but it does not give satisfactory results.

I’ve been looking into multiple existing threads with almost the same issue, but none of them seem to solve my challenge.

I’ve attached screenshots, 3DM file and GH file with curves.

Thanks in advance,



Sweep2_issue.3dm (172.8 KB)
Sweep2_issue_GH.gh (6.3 KB)

Banking the roadway, perhaps? That could be done using Sweep1 by rotating the pFrames (actually, it happens automagically due to torsion), but this uses Sweep2.


Sweep2_2025Jun3a.gh (14.2 KB)

This makes so much sense - thanks a bunch!