R8 - Boundary Surfaces Component Failure

Grasshopper
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Hello,

I believe I found a new bug in Rhino 8 Grasshopper with something that was previously working in beta (and prior versions)

In some cases (such as the file attached) the Boundary Surfaces component fails to yield a result despite it having a closed polyline. (A)

Oddly, if I explode the polyline in question, sort its vertices by the polyline itself via Sort Along Curve, and then construct a new polyline from said sorted vertices, the Boundary Surfaces component works as expected. (C)

Alternatively, If I use the cull duplicates component on the Polyline control points and then create a polyline from the culled vertices, that also works. (B)

I thought perhaps the segments being joined were facing opposite directions, causing some kind of glitch but I used the dir command in Rhino to ensure they are all running counter-clockwise and still am having the same issue.

I have a feeling the underlying issue is related to what it considers a “closed curve” and if the rhino polyline has the extra vertex, it considers it open technically. This is evidenced when you use the Control points component on a rectangle or square, you always get a 5th control point at the seam location. Just my guess…

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image1390Ă—550 70 KB

Thanks for your help!

20231114_Boundary_Surfaces_Join_Curves_Bug.gh (13.2 KB)

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I think it is not a closed polyline.

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image2032Ă—850 116 KB

Here:

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image608Ă—572 3.12 KB

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That would make sense and also make sense why building a new poly line works because it’s connecting the “miniscule gap”.

Thanks!

EDIT:

That was it, works great now. Thanks @Quan_Li . I didn’t bother checking that since I derived the multiple segments from a polyline I split earlier but I must have split at just slightly not the corner or accidently deleted the segment at that location.

I appreciate the help!

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