PlanarSrf produces surfaces with inconsistent isocurves

Rhino
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1

Hi.
I’m creating planar surfaces from planar polygon using PlanarSrf command in Rhino. I have two very similar closed planar polygons which I created planar surfaces out of them. Both polygons have the same orientation. The question is why I’m getting different orientation of the underlying surfaces and consequently different directions of isocurves? How Rhino decides upon the underlying surface?

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different_underlying_surfaces.3dm (62.4 KB)

2

Where are the end points on the two curves?

3

They are identical. The curves are actually copies then I slightly moved one of the vertices

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4

Interesting

5

RH-88953 is fixed in Rhino WIP