Sorting loft out once and for all?

[brooks]

I know loft is a little finicky in general, and I have learned to iterate on loft problems by making sure curves are all in the same direction, sorted correctly, seams are aligned, making sure either no or all curves are kinky, and then adjusting the number of input curves until it works.

But I’ve got this file that is just not cooperating, and the problem does not disappear with any reasonable number of input curves.

Curves look normal:

…but the resulting surface has an unpleasant twist:

Here’s a very simplified file with the data internalised:

loft-problem.gh (269.6 KB)

Any ideas of how to solve this in a general way?

[Joseph_Oster]

Still a bit rough but better? Moved the seams to match a spiral (created by eye).

loft-problem_2021May8a.gh (278.7 KB)

[brooks]

Oh, interesting. It’s an optimization problem for where to put the seams. Looks like they want to be far from curvature. Thanks!

[Joseph_Oster]

I think the seams are only part of it. Those curves are not all fair, they wiggle, causing ripples.

[brooks]

As usual I’m blown away by quick insights and help. Thank you so much! With that knowledge I’ve been able to adjust the seams earlier in the process so the first loft happens with the seams aligned to the middle of a length side. The curves still aren’t perfect, but I’m working in clay to the wiggles are far below the material’s tolerance anyway.