Overlapping and twisting in Loft result

I’m getting a strange result from a lofting of closed curves that I’m having trouble resolving. I tried a sweep as well and the results were also problematic. Not sure what I’m doing wrong. The ends seems to be overextending and twisting. Thanks for any help!

loft_help.gh (77.0 KB)

  1. Your curves are far away from the origin. This can often cause obscure problems.

  2. Loft works with the output of your first 2 Fillet functions if you Flatten Loft’s Curve input and set the Loft Options to Closed Loft. I don’t have Pufferfish so I couldn’t do anything with the 3rd Loft.

Your geometry looks like the frame for a bicycle seat. Maybe that will pique David’s interest to help you.

loft_help.gh (60.6 KB)

Here you go, there was small problem here. I mentioned where.

As you can see, the very last curve output from Join is not closed which causes Loft to fail with this error message:

  1. Loft only works if all curves are open, or all curves are closed.

Adding Shift List with ‘S’ input of -1 and ‘W’ input False (inverted) removes that curve from the list. Then you need to right-click Loft ‘O’ (Options) input and check ‘Closed loft’.

loft_help_2020Dec15a.gh (77.6 KB)

I make the section curves planer (the offsets were not in same plane), which in return created clean fillets, so all curves were closed and the loft worked properly. Hence there was no need to remove any curve from list.

You were more thorough than I was. I only noticed later that the section curves were not on pFrames so were skewed from perpendicular, which is a good clue that something was amiss in creating them.

I also see a Line param at the beginning that contains 200 lines with no obvious correlation to the Divide Curve points, which is rather odd?

Yes, it is weird approach to begin such code. I found the the principle curve of sections (after first fillet) and saw that offset curve plane was amiss.