What is NonmanifoldMerge?


I’m a new user. I’ve just discovered NonmanifoldMerge. It seems to “join” polysurfaces that the Join command won’t (intersecting curve extrusions and revolutions). Clearly, I don’t understand what I’m doing here. (I think I know what a non-manifold edge is, but I don’t know why it’s important.)

Can anyone suggest, e.g., a tutorial that might help me sort out my confusions about Join versus NonmanifoldMerge? Thanks.


Well I have an old blog post about NonManifoldMerge at http://hydraulicdesign.blogspot.ca/2010/10/non-manifold-edges.html

Basially, unless you’re exporting to FEA, don’t use it, for any other purpose(inset caveat about 3d printing hollow objects here) it creates what is considered “illegal” geometry that no downstream application is going to accept.


Don’t use NonManifoldMerge unless you are trying to create disjoint solids. This is principally an experimental “expert user” command.

For “joining” intersecting volumes, use BooleanUnion.



Thank you both. I think I’ll just avoid it.