Cousins of the Bisect tool and 3D printing

Hi. Are there any cousins of the bisect tool that, like it, can make cuts to a mesh, either side of which will be perfectly matched to the other? Some might notice that the Solidify modifier, when it creates a rim surface from a surface that it thickens, doesn’t assure that corresponding rim surfaces (if solidify is performed on both sides of, say, the two parts of a UV sphere that has been bisected) will be perfectly matched in terms of their rim surface angles relative to each other. That is a concern, because my aim is to create thin shelled surface parts that mate well for 3D printing. Here’s an illustrative example of that using such a UV Sphere.


I request any help from others experienced in making 3D printed models whose cut and thickened sections must mate well. Thanks.


I think that your problem would be solved if you use the solidify first, and then you cut your object… Isn’t it ?

See you :slight_smile: ++

May well be. Unfortunately, bisect wouldn’t be too appropriate for that, since it deals only with planar cuts, and my cuts are sometimes long and irregular (say up and down the sides of a character’s body making for front and back halves). In the solidify then cut/bisect scenario, the process of rebuilding mated rim surfaces after the bisect seems to be long and tedious anyway and I’m hoping for a more direct approach. Thanks.


Greater resolution, say after a subdivide or two might help with the solidify artifact, if cutting before two matched solidifies.

Ok I see. Then, here is what I would do :

  • Assuming that you know where you want to cut, you can select all vertices from one part
  • Apply solidify modifier
  • Go back to edit, and make a new object from selected vertices (P key)
  • Select non manifold (edge mode) and do a bridge edge loop on each part, in order to close the mesh

I did a quick video for you :

See you :slight_smile: ++

1 Like

Thanks, Tricotou. I’ll be experimenting with your approach. Will let you know how it turns out! But it, at a glance, does look like the exact solution I’m looking for.

I like these video demos, but BlenderArtists could benefit from the Autodesk approach to them that preserves record of hotkeys and such in a timeline that are often easy to miss, particularly with youze guyz who are so experienced and fast on the interface such that us slow old folks have trouble keeping up with you, even as we’re impressed with your speed. Thanks for the quick response. I’ll go ahead and mark it as the solution (and liked). Nice outfit by the way. Always wanted one of those. But aren’t you a little short for a stormtrooper? :smiley:

Glad to help :slight_smile:

Yep in fact there is an addon that prints the hotkeys on the screen, but I did’nt enable it before recording my video, as I explained what I did :stuck_out_tongue:

It suits me like a charm xD

See you :slight_smile: ++

1 Like

So does your solution, I believe.

I’m curious how you were able to select faces so quickly. I only know how to select each of them individually. You just ‘painted’ to select.

If you are ever part of the parade down Peachtree Street here in Atlanta during Dragon Con, won’t you please tell me how to get a copy of that poster of the cutie with the technicolor pink hair, the cat ears and the gorgeous smile while holding a tot, as I recell. I MUST HAVE HER!

The C key enables “circle” selection
Then mouse wheel sets the size, your can select with click, and unselect with mousewheel click

Whôt ? :troll: I think I missed some chapter there :joy:

1 Like

A squad of stormtroopers are an obligative part of every year’s Dragon Con parade. And the obligative cutie has also popped up from time to time on banners also along Peachtree Street (in support of fundraising efforts of some charity for tots I believe). But she is priceless.

Ok :see_no_evil:

You must know that my profile pic is a Blender Cycles Render, and to be honest, I’m not an actual StormTropper ahaha :smiley:

Oh. I thought you just might have been one of the few, the proud… the dudes lucky enough to have a stormtrooper costume… that Vader regularly leaves to garrison the city for a few days during the yearly Dragon Con convention. I’m still waiting to see twin Vaders battling with light sabers.

I’ve gotten to the point where you snatch out the two coupled outer and inner surfaces, but I lose you when you are somehow able to click up the help dialog where you bring up Bridge Edge Loops, then deftly the non manifold selection. Is that quick search dialog a a third party add-on? If shipped with Blender, then ignore me while I thrash around and I’ll find it eventually.

Gave you a ‘solution’ and a ‘like’ for each of your: 1-mention of the addon, 2-explanation and excellent video, 3-mention of C circle selection. Oops, I see there is but one ‘solution’ per post/issue. But I’ll give you yet another ‘like’, if you show me the way to the quick search tool too. Thank you so much. You’ve been incredibly helpful. :joy:

For the benefit of others I’ll synopsize your solution with max clarity:

Make a UV sphere then… In Edit Mode, select all faces to serve as the outer surface of the shell section (the C key enables quick Circle Selection). Back out to Object mode, Apply the Solidify Modifier. Back in Edit mode, Seperate by Selection the faces/vertices. Back to Object Mode, can pull out the outer and inner surfaces coupled together with G. Select->Select All by Trait->Non manifold to select the peripheral edges. Then Mesh->Edges->Bridge Edge Loops to turn them into faces for precisely aligned rim edges of thin shells made from surfaces.

He’s using the search menu, spacebar.

Select non-manifold is in 3D view select menu, hotkey ctrl+alt+shift+M. Bridge edge loops is in specials, W.

Redo history is also useful when calling back previously used operators, hotkey F3.

1 Like

Yep the search is with space bar :slight_smile:
I could have used the short keys but I specially used the space bar here in order for you to have an eye on the function name :wink:

See you :slight_smile: ++

1 Like

Oh… I didn’t know it would be such an intricate, involved, complex route to that solution. If I were careless, I might have found it with a careless tap of me thumb! :crazy_face: