Simple Nonmanifoldmerge Model

Rhino Developer
1

@dale , @Bill_Cook , @GregArden ,
MergeProblem.3dm (81.1 KB)
Trying to run nonmanifoldmerge on a simple closed volume and a surface; the resulting nonmanifold volume is invalid. I don’t see any obvious issues that would cause the problem. The model is attached.

Thanks, Larry

2

Split or Trim the surface by the solid, then NonManifoldMerge. The result will be a valid polysurface.
MergeProblem_DC01.3dm (2.0 MB)

3

Thanks David. We also found some similar workarounds, but within Orca3D internally I’m not sure we want to do that generally. This was from a customer who was using the Orca3D subdivision functionality, so I’m hoping that McNeel is able to find what is causing the issue. Thanks as always for your input.

4

Hi @LarryL,

I’ve logged the issue so we can investigate.

https://mcneel.myjetbrains.com/youtrack/issue/RH-81294

– Dale

5

Many thanks @dale !

6

@LarryL,

The two surface input has naked edges where it should have a single joined edge. Because of this, the merge ends up with slits which are considered bad. If you explode and join those two surfaces, the result of NonManifoldMerge is good.

Any idea how that thing was made?

– Dale

7

@dale , that’s a very good question! We are checking back with the user to see how they were created; sorry I missed that (I was focusing on the wrong surface)

Larry