Closed Sweep that Will not Cap

I was trying to create a solid from the attached file. i have two planar curves (red) and intersecting lines (purple). The upper planar curve is two semi-ellipses joined by two lines. The bottom curve is a circle.

If I do a a sweep2 and cap, the opening at the circle will not close.

If I do a networksrf with all the curves, cap creates a solid.

This seemed like odd behavior so I share.

Problem (17.9 KB)

Hello - I see that - the sweep surface falls off of the rails by quite a bit. If you want to fix it, MatchSrf to the circle, then cap. I’ll get this on the pile, thanks.
If you can live with a rebuilt (24 points, degree 5 works well) circle, that works better. I think the problem arises due to the rational curve there with a true circle.

RH-61951 Sweep2: Misses the rails


This was not a roadblock. Whenever I see something odd I try to reproduce and post.

often circles are a bit clumsy (degree 2 with weight and special Knot-settings) for building surfaces.
If you _split the Circle into 6 parts first (use rails / endpoints as cutter) - and join them together
it works fine here. (on a mac)
…and for many purposes - one is, to get things / (untrimmed) edges … planar - i can recommend
_setPt (only set Z-Value …)
_cap will work … just if somebody reads this post later with a cap proplem

  • best -tom