Preventing the double edge


It seems Max is still notorius for double edges. Take a plane and cut it in half. Now grab the two edges at one end and extrude them together. Insead of keeping one edge between the new geometry, it in fact adds an extra edge. Oddly enough you can weld the new verts together but the double edge remains. I am finding this issue godamn impossible to fix. Unless you count cutting out your polys and re-trying using a slow approact to modeling.

I am wondering if there is some kind of trick to extruding two connected edges together without max inserting an overlapping edge? It is also annoying because the two new edges are right ontop of each other and it often looks as though everything is ok. Until you export of course or use the meta-nurms trick for spotting it.


I’ve had the same issue, and at present there doesn’t seem to be a quick solution. Shift-dragging open edges works fine, but closed edges don’t.


Draging open edges hmm. I’ll try doing some tests on that later. It somewhat has me puzzled how we are at max version 7 and yet this situation has not been yet fixed. Perhaps through the use of maxscript someone from the community may make a work around? Then we could hotkey it so we can toggle to a proper edge extrude function.


In the past, the only way I’ve been able to fix it is by splitting the edges I want to extrude, then re-welding them. It’s a sucky way of doing it, but it works, and saves going back over every edge extruded to remove faces.


It sounds to me like your problem has something to do with the fact that Max polygon objects are manifold meshes, meaning that any single edge can have no more than two faces connected to it. And the reason you can’t weld that additional edge away is that Max actively ‘disallows’ the creation of non-manifold meshes. This is something which no amount of scripting or even fiddling with the SDK will get rid of.

If you want rat’s nest meshes (an affectionate term for meshes with more than two faces per edge) you’re going to have to use Edit/Editable Meshes as your final step of the modelling process to get rid of the double edges.


Re-reading what I initialy posted, I don’t think that would reproduce the problem, but it seems Erilaz had no problem grasping the issue I was trying to get across anyhow.

However, I am confused at the work around by splitting the edge you want to extrude? Wouldn’t this cause more edges and more problems to fix? Or do you mean, split, extrude extra edges as well, then kill center poly, and then weld other edge into place?


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