Solid by loft - Centerline is not G1

I have a problem with Solid.By.Loft - Unable to set the sections or the centerline! : CENTERLINE_NOT_G1_CONTINUOUS – Centerline is not G1.
There are two profiles made in revit as line on referenceplane and a path made of some curves. First profile is at the start point of polucurve path second one at the end.
Have no clue what i’am doing wrong? Any ideas? Or is there another way to do so.

Thanks for your help.


Apologies I’m not at a PC to give a full answer, but it’s possible your Polycurves aren’t closed.

Try getting the end points from the lines and doing Polycurve by Points… That node has a Closed option for the Polycurve.

Hope that helps,


I’ve checked curve.isclosed, and tried as you said, but still nothing.

Perhaps simplify… get it working with 2 squares and a curve… then gradually increase the complexity and see at which point it fails?

It’s difficult to anticipate which of the complexities you have is the problem one :slight_smile: it may be several of them…

Hope that helps,


ok, it seems that if polycurve have sharp egdges it doesn’t work. Any ideas to solve that problem?

Agreed, I cheated…

Dynamo doesn’t have the tools maybe…

I split the smooth lofted solid at the points of the curve, to give intermediate profiles, i then paired these and lofted, to give the angular solid, which I unioned.

I created a nurbs curve (this can’t be too angular or it fails) to generate the smooth lofted solid, it would probably work on your filleted polycurve as well.

Hope that’s of interest,


SweepFromPolycurveGuide.dyn (34.2 KB)

Thanks for help.

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The curve you are using i not G1, meaning that is continuous, but not its derivative, meaning that you have changes in slope (cornerpoints). The loft function won’t work with that curve, you need to use a smooth curve, Nurbs is one.
Hope this helps.