Lofting with scaled ellipses - I want surface but GH creates Brep

I’m lofting two curves. Each is a portion of an ellipse (degree 2) (with no kinks).

When I loft in GH I get a polysurface with two faces. I can rebuild the curves but I’d rather not - I’m keeping the geometry as clean and as lightweight as possible.

They loft happily and as expected in Rhino. Am I missing something obvious here?

See attached GH file.
question.gh (13.8 KB)

Thanks

If you used part of an ellipse, the ellipse has 4 kink points, so it is likely that kink is included in some way.

You could use Ruled Surface or Pufferfish plugin’sUnsplit Loft Surface instead.

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Good point about the ellipse kinks. However:

  • it lofts without splitting until I scale the ellipses.
  • IsCurveKinky (also from pufferfish) does not find any kinks.

So I’m wondering if there is something else happening here.

Unsplit Loft Surface works perfectly though - thanks @HS_Kim :+1:

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I did a little test with a C# component and Brep.CreateFromLoft creates a single surface. I suppose the loft component does some extra things.

You can reduce the Rebuild ‘N’ (Count) value from 100 to 5 and still be very close to the original polysurface.

P.S. Any reason to be working so very far from the origin?

Thanks for the reply but 5 control points leads to up to 75mm difference between the curves - much too large.

On curves that are 75853 mm and 129037 mm long. That’s less than 1/10th of one percent.