V6 - Weld Vertices not working


i am trying WeldVertices command…:



Post your model and I’ll run it through the debugger and see if I can figure out what’s going on.


model is here:
weld_model.rar (140.9 KB)

OK. Thanks for the file and I can replicate the problem. I’ll dig into this on Monday and let you know what I find.



This will be fixed in the 6.6 service release.

In V6, the command was not replacing the object in the document if it failed the validity test. In your case the object was invalid (one face had two different vertexes with the same 3d location) prior to running the command so it would have never succeeded.

This fix removes the validity requirement and notifies the user when the output is not valid.

In the meantime, you can run CullDegenerateMeshFaces to get rid of the problem prior to running WeldVertices.


RH-46170 is fixed in the latest Service Release Candidate

Great! Thank you very much.

Sorry to jump into this topic after a year that has been closed but I still have the issue in 6.17 with the attached file. In Rhino 5 with 180 degrees tolerance the full mesh is welded. In 6.17 it is not.

WeldBroken.3dm (75.1 KB)


Hi Alberto - so far I do not see a difference between the V5 and 6 weld - if I unweld the mesh and weld in 5 and 6, I think I get the same result - I’m not sure if that is a good test for what you are reporting? If I ExtractPt from the welded mesh then SelDup, they have very nearly the same number of duplicates (i.e. unwelded vertices) - V6 does have a couple more - 102 vs 96 - is that what you’re seeing?