Loop selection seems a bit broken in 3.2?

[Tomoko]

Ever since the new update, trying to select loops on the edges of objects seems to be... broken? Like, if I have a cube and place a loop cut through the middle, loop selection can select that entire loop. But if I try the same for the loops around the edges, it only selects one "side"s worth of loops, not the entire loop. It's as if the topology is broken, but... This has applied to basically every object I've made so far, didn't happen in 3.1, and the topology clearly isn't broken as I can still place functional loop cuts.

Is this a new setting that was introduced? I don't read patch notes for the most part.

[*P0P$*FR3$H3NM3Y3R*]

Are you sure this didnt happen in 3.1 too? I went back to a 2.83 and a 2.9x version and this behavior is consistant. As in IF the loop i ssurrounded by adjacing faces it selects the whole loop but it only selects a single edge when using it at the outside edges.


So I think this was always this way, also because what connected edges it is supposed to be using would be ambiguous,. Lets say you want the loop at the top, so you ALT click on one of the edges on the top, but how would it know to select the top ring and not the one that forms the side face?
It still selects the whole loop if theres no face connecting the edges.


Yeah 3.1 acts the same: I downloaded that to check aswell.
https://i.imgur.com/1BeBXj1.gif

[Tomoko]

Originally posted by *P0P$*FR3$H3NM3Y3R*:

Are you sure this didnt happen in 3.1 too? I went back to a 2.83 and a 2.9x version and this behavior is consistant. As in IF the loop i ssurrounded by adjacing faces it selects the whole loop but it only selects a single edge when using it at the outside edges.


So I think this was always this way, also because what connected edges it is supposed to be using would be ambiguous,. Lets say you want the loop at the top, so you ALT click on one of the edges on the top, but how would it know to select the top ring and not the one that forms the side face?

Yeah I went back to 3.1, 3.0 and 2.93 and it happened in those versions too. I'm starting to think this is just normal behaviour and I never noticed, but it's such useful behaviour that doesn't seem to work intuitively.

[*P0P$*FR3$H3NM3Y3R*]

Originally posted by Tomoko:

Originally posted by *P0P$*FR3$H3NM3Y3R*:

Are you sure this didnt happen in 3.1 too? I went back to a 2.83 and a 2.9x version and this behavior is consistant. As in IF the loop i ssurrounded by adjacing faces it selects the whole loop but it only selects a single edge when using it at the outside edges.


So I think this was always this way, also because what connected edges it is supposed to be using would be ambiguous,. Lets say you want the loop at the top, so you ALT click on one of the edges on the top, but how would it know to select the top ring and not the one that forms the side face?

Yeah I went back to 3.1, 3.0 and 2.93 and it happened in those versions too. I'm starting to think this is just normal behaviour and I never noticed, but it's such useful behaviour that doesn't seem to work intuitively.

Well if you still need the loop you can simply select the whole face, or delete the face and get the behavior of a normal loop / circle.

[Tomoko]

Originally posted by *P0P$*FR3$H3NM3Y3R*:

Originally posted by Tomoko:

Yeah I went back to 3.1, 3.0 and 2.93 and it happened in those versions too. I'm starting to think this is just normal behaviour and I never noticed, but it's such useful behaviour that doesn't seem to work intuitively.

Well if you still need the loop you can simply select the whole face, or delete the face and get the behavior of a normal loop / circle.

Face selection does work for quite a few things, but it doesn't work for everything:
Currently, I have a box that has thickness in walls. It has a "square" base with a hole in it, so it's the same issue with the edges when I want to add seams to unwrap, but it's more clicks to select the faces and unselect the edges, than it is to simply select the edges themselves, which just wastes a bit of my time frustratingly.

Likewise, boolean holes from cylinders don't seem to be edge-selectable which is quite annoying as I use that functionality a lot. Not really sure why they can't be selected in this case, but probably the same issue. Face selection ironically works with them and I can still add loop cuts all I want, just selecting the edges doesn't want to play nice.

[*P0P$*FR3$H3NM3Y3R*]

It's probably a limitation of the algorithm. I don't know how it identifies the verticies in a loop, I guess it looks for all connected verts that have the same traits like ammount of adjacent edges hence it stops once they mismatch, but thats just a guess.

[Tomoko]

Originally posted by *P0P$*FR3$H3NM3Y3R*:

It's probably a limitation of the algorithm. I don't know how it identifies the verticies in a loop, I guess it looks for all connected verts that have the same traits like ammount of adjacent edges hence it stops once they mismatch, but thats just a guess.

Yeah I believe it's checking for it to have four adjacent edges so that it can gauge direction and loop "flow", and since corner sections only have three or two edges, it can't do that as easily.

[The Renderer]

It can only select clearly defined loops. Loops going along quads (same as when you can and cannot create a loop cut with ctrl-R).
Edit: Or, better described, as you just did, it needs 4 edges at a vertex to continue the loop.

The edges of a cube are not a clearly defined loop. How is the algorithm supposed to know which way you want to go?

If you boolean cut a cylinder you end up with undefined loops as well, since you (usually) do not have nice quads there.

Has always been this way, will always be this way, the algorithm cannot read your mind.

[Tomoko]

Originally posted by The Renderer:

It can only select clearly defined loops. Loops going along quads (same as when you can and cannot create a loop cut with ctrl-R)

The edges of a cube are not a clearly defined loop. How is the algorithm supposed to know which way you want to go?

If you boolean cut a cylinder you end up with undefined loops as well, since you (usually) do not have nice quads there.

Has always been this way, will always be this way, the algorithm cannot read your mind.

Well the boolean cylinder one has pretty neat geometry, so not really sure what's going on there given your respond.

I'm just a bit annoyed that parallel loops to the edges can be selected by these edge ones that are functionally nearly identical can't be selected, despite behaving in almost the exact same way. There really isn't that much "mind reading" required, as you seem to imply.

[The Renderer]

Hm, that's weird then (with the cylinder). Do you have a screenshot?
Edit: If you e.g. simply cut a hole through a cylinder, it may look neat, but it isn't at all, since the front and back face will be ngons, you cannot loop select those, as explained above. If you make it all quads around the edge, you will be able to loop select the rim.


Yeah, I understand your issue, but it may be intiutively clear to you where the loop should go, but mathematically it is not.

[Tomoko]

Originally posted by The Renderer:

Hm, that's weird then (with the cylinder). Do you have a screenshot?


Yeah, I understand your issue, but it may be intiutively clear to you where the loop should go, but mathematically it is not.

Maybe I should just create a plugin that tries to do exactly what I want. It'll solve both my issue, and maybe help others.

Or I'll discover why it isn't a feature by default, haha.

[The Renderer]

Sure, such a plugin would be well received. :)

Did you try selecting one edge and then using one of the select -> similar options? Like face angles. Might work a little better, depending on your geometry.

[The Renderer]

Also don't forget you can select the shortest path via ctrl, that should also help select a pseudo-loop quickly.

[Mark3]

A selection of the interior faces as was suggested above, followed by a Select/Select Loops/Select Boundary Loop works fine in the cube type scenario, where corners break the loop selection process. Since it deselects the faces, and leaves only the boundary edges selected. Note that a side with no interior edges will let you loop select, but it also selects the face. In the cylinder with a hole, and end faces being non quads, then have just the end you want to work on visible (or deselect the unwanted edges afterwards), and use Select/Select Similar/Length. To be frank, the inconvenience of making a couple of extra clicks to select an entire edge loop is hardly worth losing any sleep over, if the mesh is well formed, then selection is not much of an issue. If your booleaned cylinder example, uses the same number of sides in the cutting object as the original shape, then you can easily make the end faces into quads, by triangulating, then using Face/Tris to Quads.