Faces that close but should not

[Jean Lemire]

Hi folks.

See this SU file. The text in the file explain the problem.

Faces that close but should not close.skp
I wonder what is causing the problem.

Best regards.

[Aerilius]

That is interesting.
It is not caused by any inaccuracies around SketchUp's tolerance (this is often a reason for weird behavior), all joining edge segments meet at [0.0, -20.1771653543307, 25.3818897637795].

Actually it does not matter where you start the arc (at any end point of a planar loop of edges), it triggers SketchUp's automatic face closing function.

[jeff hammond]

using a line doesn't trigger the behavior.. using the rectangle tool does..

[thomthom]

@unknownuser said:

using a line doesn't trigger the behavior.. using the rectangle tool does..

Maybe the tools, Arc and Rectangle, runs edge.find_faces on all connected edges instead of only on the newly added edges? Where the Line tool does it on all just the new edge.
Just wildly guessing.