Closing non-manifold meshes

I’m new to 3d modelling, but i’ve figured out how to do a lot of what i need to do, even if it might not be the most efficient method. That is, with exception to closing the edges on non-manifold meshes. There are a lot of automated closing options in fusion 360 but none of them even come close to achieving what i want, and i’ve tried adding faces to the separated vertexes manually in blender but it’s so complicated and finnicky it’s almost impossible, and i feel there has to be a better way.

Attached is an example of a model i need to close. There are essentially 2 completely seperate objects which i need to join the edges together.

Any kind of guidance on which software would help me accomplish this and how would be appreciated, thanks.

In my experience, closing meshes has started at how to model. So it would be great if you could explain the tool and workflow you used to get to this model in the first place. By far the easiest of which I’m aware is if there is an alternative workflow that creates a manifold in the first place.

I have used meshlab to repair non-manifold meshes before. It has lots of functionality and thus can be intimidating to get started with. However, I have not tried to close two offset surfaces in it like this; I don’t know if that’s easy. I would guess that you would have to at least identify some initial vertices to join and then see if it has implemented one of the algorithms to iteratively fill gaps, once you go from two faces to a single face by joining with at least one polygon.


Unfortunately this is not a model I have built myself, but an STL I downloaded.

Well, then, I’d give meshlab a try. They use stackoverflow for Q&A. I’d suggest providing a link to the STL and not just showing pictures in asking for help with it though.