How can I avoid getting this seam?

On a closed curve running Pipe method.

Can the method/command be massaged where it would rather use one of the corner seams if those exist?

Hello- use CrvSeam on the input curve.


Curve Seam is not where the pipe seam is dropped though:

the Pipe command seems to be dropping Pipe seam ̶w̶h̶e̶r̶e̶ ̶t̶h̶e̶ ̶c̶u̶r̶s̶o̶r̶ ̶i̶s̶ mid arc(?) and Pipe rhinocommon method is random(?).

Hello- please post that curve.


test curve and pipe.3dm (380.2 KB)

Thanks - I never noticed this before but Pipe puts the seam on kinked closed curves in the middle of one of the curve segments - never on a kink- that makes sense, so that the cross section circle can be made.


The problem is that if I’m trimming a surface with that pipe, the new surface will get a kink on that arc edge and I have no idea how to fix that without making a new surface.

And why is it not using simpler geometry, like Lines (that I can geo.Edges.MergeAllEdges() afterwards). It specifically picks Arc to drop that seam at, which geo.Edges.MergeAllEdges() doesn’t work on. Surprisingly, commands do merge it.

It looks like it uses the first available segment in the polycurve, from the start point. I was able to make it use a linear segment by moving the seam (CrvSeam) more than one segment away from that arc.


Maybe MergeAllEdges() can be massaged to merge those arcs then? Just like the commands can.