Hi DesuDeus, take a look at the attached 3DM file box_with_split_edge.3dm

If you select the top front edge, you'll see it is actually not just 1 edge but 2 edges there, like this:



You can use the Merge command to glue edges that are split up into fragments like that back into longer edges.

For example, select those 2 edges (or the whole box) and then run Merge by typing <tab> Merge <enter>.

Now when you go to select edges there you'll see there is just one edge there - the merge command combined the 2 edges that touched end-to-end into just 1 single edge.

For edges to be mergeable like that, they need to be only 2 edges coming off of the spot where they touch, and the edge curves need to be tangent to one another (not have a sharp corner where they touch).


Sometimes you can get split up edges like that from various things, this allows you to repair those.


In the future at some point it should also get applied to curves and surfaces as well, as a way to merge 2 curves into a single curve segment, or 2 surfaces into a single surface. That's unlike Join which glues things together but results in a segmented (for curves) or multi-surface (for surfaces) object which can be broken back into its individual parts with Separate after that.

- Michael