Unifying Normals fails

Rhino Rhino for Windows
1

This is strange. I thought I had done this kind of thing successfully a hundred times before, both manually and in GH, but today for some reason I fail to unify the Face Normals on this mesh. Some faces remains flipped no matter what I try.

Does someone else here know what steps to take to unify this mesh? But if not, why doesn’t it behave?

image
image812×372 189 KB

Stubbornly Not Unified.3dm (544.9 KB)

Please be kind to me when you have figured it out… :blush:

// Rolf

2

Hi Rolf - use ExtractNonManifoldMeshEdges first, then unify.

-Pascal

3

Thanks! That did the trick.

Has the mesh changed lately and become more picky? I don’t recall ever using this command… In any case, now the meshes behave again.

// Rolf

4

Hi Rolf - if there are non-manifold edges, unifying can’t possibly know what to do…

-Pascal