i created an ultimate test file with lots of cases:
rows are the methods/workarounds i tried:
- method 1: simply using the loft tool
- method 2: breaking up the faces into smaller pieces by adding lines to it. all smaller pieces have 3 points only. it’s like triangulating my face except i still have some spline edges.
- method 3: i had another idea for a workaround that would be faster (in terms of making the loft itself). it’s breaking up the splines into smaller splines to have start and end points only. it turned out to be a tedious process because using the break/join constraint change the shape of spline itself so i needed to use the trim tool and remove every other section then draw another spline and trim what remained from the first one.
here is a screenshot about the two workarounds:
columns are the shapes i tried to loft. i used the intersection points on 2 different planes to draw the 2 similar shapes:
- shape 1: line + spline with 1 curve point
- shape 2: line + spline with 2 curve points
- shape 3: line + spline with 3 curve points
- shape 4: line + spline with 5 curve points (this is what i used above when i discovered this issue)
- shape 5: simple triangle, it cannot be simpler than this. i added this at the end after failing with everything else and this didn’t work either.
guide curves:
to make it simple i used simple arcs this time. i drew some concentric circles and trimmed them to leave a quarter only. then i rotated some of them around the Z axis.
results:
| spline 1 | spline 2 | spline 3 | spline 5 | triangle | |
|---|---|---|---|---|---|
| no workaround | failure | failure | failure | failure | failure❗️ |
| smaller faces | failure | failure | partial success | partial success | - |
| broken spline | failure | failure | failure | failure | - |
i even tried to use the two workarounds at the same time to have small faces surrounded by small spline sections only and that was a failure as well. i just didn’t have time to add a fourth row.
in all cases i could use one or more guide curves but when i added all i got various error messages, see my earlier comments. i tried all the combinations, i tried to add them in different order and nothing helped. the only partial success i had was with some small faces but i couldn’t finish the full loft.
i attached the file to help debugging this.
loft-bug-ultimate-test.shapr (149.0 KB)