I ran into a situation with my latest model where I was not able to select the top border edges all the way around the edge loop for some reason.  It's not because the vertices aren't welded, they are.  It was a cylinder modified by modifiers to change the edge direction.  A technique I learned to do while following a tutorial intended for another application.  Normally, holding ALT+RMB would select the entire edge loop around.  But now, after changing the direction like this, it doesn't.  It only selects two of the edges in the open edge at a time.  Not a big deal, since there isn't that many edges, but I've seen in other software that there's ways to select these border edges all at once, regardless of the edge direction, and I'm wondering what I could do in Blender to make that happen?  If I had a lot of edges here, this would be very time consuming.

Again, I tried all the standard ways, like ALT, SHIFT+ALT, etc.  Nothing works now.  I looked in the manual for selecting "open" edges, or borders, but there doesn't seem to be anything documented on how to do it.  Probably because it's not a common situation to occur.

Oh, here's a screencap of the object, showing what I mean.

Hi HMorton

Simplest method that I know of to get all the edges selected like what you are attempting is

1 Go into wireframe (in edit mode hit Z and will be in wireframe)

2 make sure you are in vertices selection hit B for bounding boxand select all your top verts (this usually works best if in Front Camera Ortho

3 with all the verts selected which I assume from your photo would be the points that look like triangles change from vert select to edge selection and all your edges will then be selected so you wont have to select each indivual edge one at a time.

Hope this helps might a step or two more than you want but once you do it a couple of times really not time consuming at least thats how I would accomplish it. Sure someone might have a even shorter route

 

Good Luck

in the posted image there is what appears to be a remnant which could just be a orphan vertice or it could be a derrivitave vert that is linked to the mesh somewhere

if it is an orphan it should be deleted but if it is linked it could need to be welded to its parent or deleted

yes something that minor can cause the issue that you are having

another cause is that the mesh is over modded there was no need for so much geometry

what happens when you add the points is that the edges break to resemble a square

if the mesh requires that the faces be turned then you can just use the box select tools to catch the top edge verts but it the added mods are just for looks for now i would have started with a circle at 16 verts, select the circle and subdivide once, then extrude that and scale it, then grab every other vert on the top loop and scale them up or just drag them up using the grab tools

you get the same effect but it is still a single loop and easier to texture and map later

i gave the design a once over and this is what i got

 

 

Check for double vertex.  I know the style you use here, I have done it so too.  This technique is for making like the object I post, and other type like it.  Results are good.

I learned too from the window tutorial how to get the edges.  It's a good geometry, but you might have double vertex.  Blender can not select border as you wish on some type of geometry, and that's just a fact.  Maybe some software can do so, but it depend on if the edges compare a complete loop, or if they have more than one pole? 

Thanks, Lobo3433.  Selecting the vertices with box-select (B), then converting to edges works well enough.  I didn't think about that.

Zandar: BINGO!  That's exactly the sort of object I'm working on.  Again, trying to follow a tutorial which isn't meant for Blender, but seems to translate well enough.  There's a few extra steps, but not a big deal.

Here's what I was after, guys.  Created this from another software's tut.  Had a few problems early on, like with the selections, and then making the holes.  The tutorial in question was using "inset" to create the latticework from the criss-crossed edges, then delete the inner faces, leaving behind only the cage you see here.  But our inset tool in Blender wasn't doing the job in the same way as the tutorial app for some reason, on all the faces at once.  They were using a type of "inset individual".  Our inset seems to only work on regions?

So my solution here was to bevel the edges first, then delete the inner faces, then create thickness on the resulting cage. Oh, and I after I selected all the edges at the very top that I wanted in the previous post, I applied a "flatten" operation from the Loop Tools, which made all those jabby parts flat!  I think the results are the same as the one in the tutorial, just a few more steps to get there.  I'm proud of it though. I learned the edge turning trick from following that fancy window tutorial in my other thread.  That came in handy for creating this model too.

Thanks for all the help once again, guys!  I'm becoming more and more confident with my skill in Blender, thanks to all of you!

Anyone know the best way to create cumpled up paper?  Maybe a plane with some "noise" and modifiers?

Unbroken-Fighter, I'm sorry, I didn't mean to ignore your help.  Thank you.  Although it wasn't the shape I was after, it was very helpful for future note.  Thanks again!

HMorton

After seeing what you were trying to accompliesh I remembered this tutorial I bookmarked on YouTube that creates a similar effect but instead of deleting it was used to create a bottle decanter. You might find that you can do the same thing and this is for Blender thought I would share the link to the video think you might find it useful.

https://www.youtube.com/watch?v=0rXDVF_PijA

 

Quote - HMorton

After seeing what you were trying to accompliesh I remembered this tutorial I bookmarked on YouTube that creates a similar effect but instead of deleting it was used to create a bottle decanter. You might find that you can do the same thing and this is for Blender thought I would share the link to the video think you might find it useful.

https://www.youtube.com/watch?v=0rXDVF_PijA

 

Oh, that's a wonderful tutorial!  Really elegant object.  Not quite useful for the geometry I was trying to achieve here, but definitely learned something new from it!  Love the way he created those triangulated bumps in the vase.  Wow.  So many interesting things can be made just from creating unusual edge patterns.

I'd love to 3D print a model like that.  hmmmmm.  Might be my next endeavor with Blender.  Imagine printing a vase like that, which you yourself modeled and built in Blender, and showing it off to all your family and house guests.  Amazing.

3D modeling in general is such a powerful and endless talent to learn.  There's so many incredible possibilities if you know how to model stuff.  Everything from printing still renders, to animations, to 3D printing, and so on.  I've already introduced my daughter to Blender, and she's gone through the famous cup tutorial on Youtube.  Her cup was a little lopsided, but she finished it, and rendered it in Cycles!  Quite an achievement for 11 yo!  Woo hoo! She already loves Blender.  Her next goal is to model some characters from the video game, Minecraft!   Maybe one day she'll be making games or movies in a studio. hehe.

The possiblities are endless and her learning at a young age who knows where her talents will eventually develope.