Join surfaces deform resulted joined polysurface

[gaspard.bourgeois]

I join 2 of them and it’s still OK

When I join the last one, my polysurface begin to be weird

Do you know how to solve this issue ? I put the 3dm file as well.

join_surfaces_problem.3dm (54.4 KB)

[gaspard.bourgeois]

It seems that when I cut the first surface into multiple ones, the problem disappear.

[pascal (Pascal Golay)]

Yep - _DivideAlongCreases > SplitAtTangents = Yes.

-Pascal