Ways to make round ceiling corners?

[Skaruts]

I made this a few weeks ago, but took me a while to figure out how, and quite a while to achieve it:

Now I’m redoing these models and I’ve come across the same problem. But not only I kind of forgot how exactly I did it, I also don’t think it was a very handy way to do it. Basically it involved a lot of manual control over where to cut things and a lot of merging vertices, along with a lot of snapping to align them on by one.

So I thought I’d ask around to see if there’s any less painstaking and more straightforward ways of doing this. I’d like to know how other people would go about doing this.

[RickyBlender]

one way to do it for the 4 ceilings
its too do a booleean between 2 cylinders at 90 degrees

another way would be to use the cut script !

but i think there is also somewhere a script to do these domes !

happy bl

[Sanctuary]

Maybe there’s a quicker method, but here’s one :

• Add a circle

• delete half of it
  

• go on top view of that circle and press R then type 45 to rotate it 45 degree
  

• select it all, press SHIFT+D to duplicate it, then press R and type 90
  

• select all and press W -> Remove double

• delete half of it
  

• Select those 2 vertices and press SHIFT + C -> Cursor to Selected
  

• change the pivot to 3D Cursor
  

• select all , press E to extrude and press S -> Z -> 0 (the number
  (Z is the axis for my example, in case you have a different orientation, you’ll have to press X or Y)
  

• select all and press W -> Remove Doubles

-Select that vertice and press SHIFT+C -> Cursor to Selected

• Select all, then go on the top view of that mesh and click on the Spin button

• Press F6 to edit the setting of the Spin function and set the Steps to 4 , enable “Dupli” and set the angle to 360
  

  

• Select all and press W -> Remove Doubles

• Press CTRL+N to recalculate the normals

you can set the Pivot back to Median Point if you want.

[K_Horseman]

I did it by creating a cylinder and dividing it in half, then adding a single loop cut around the middle. Then I rotated a duplicate 90 degrees to get the cross shape, then duplicated just the end edge loop of it as its own object, giving me a plain hemisphere with no faces. I saved the rotated cylinder for later (call it cylinder 2). I then used a Shrinkwrap modifier in Project mode to project that semi-circle of vertices onto the centerline of the first cylinder (thought of using Knife Project, but it was giving me trouble). Since the two had identical spacing of vertices, each vertex of the semi-circle projected exactly onto the corresponding edge on the original cylinder. I then rejoined the two objects (ctrl-J) and deleted the center of the cylinder. Bridge Edge Loops gave me a half-cylinder with the arch cut out for cylinder 2 to cross through. I merged those objects and connected the end edge loop to the open arch and voila: arched_ceiling.blend (440 KB)

Edit: Sanctuary beat me to it. His method is less fiddly than mine and he has nice pictures. But in my favor, I included a .blend file. :eyebrowlift:

[Skaruts]

@@RickyBlender

I managed to get somewhere with booleans. It requires quite some cleanup though, which isn’t ideal. But it’s one way to do it, indeed.

I’ll be looking for that plugin too. Thanks

[Skaruts]

@@Sanctuary

The only problem with this method is that you don’t maintain the correct proportions with the rest of the models. I forgot to mention this limitation I have in my first post. Sorry.

I’m doing ceilings for a 6 blender units wide corridor, and using wall “tiles” 4 BU long. So the main corridor ceiling piece is 6x4, and 3 high. For the corners I’ll go with 6x6, because it’s easier to work with and it looks good overall.

But as you rotate that initial half circle the dimentions shrink… thus my problem gets complicated. I’ll probably have to use other methods unless there’s some way to scale it precisely to the correct proportions. Snapping doesn’t usually work that well with scaling…

Thanks anyway.

@@K_Horseman

Shrinkwrap is not a bad idea too. Although the topmost vertices don’t seem to snap to the correct places. Gonna fiddle with that a bit more. Thanks.

EDIT: Nevermind, I forgot to make it Project mode. Works great so far.

[K_Horseman]

RickyBlender, every time you suggest booleans, someone comes back to you to say that it generates terrible geometry, yet you keep giving the same suggestion over and over and over. When will you stop giving the same bad advice when there are clearly far better options available?

[RickyBlender]

i think one of the the script name is Geodesic by

“name”: “Geodesic Domes”,
“author”: “PKHG (help in start the conversion: Kilon), original for 2.49 from Andy Houston”,

but i cannot make it run right now in 2.69
and it was not complete at the time

may be do a google search you might find it
let us know

but i got one for 2.49

there might be other scripts also!

thanks

[K_Horseman]

Here’s a slight improvement. A few added edge loops for better creasing along the joints, then subsurf and solidify. I applied the mirror modifier and cleared out the centerline edge loops and retopologized those faces to get a smooth curve, but if you just keep them you can get a nice peaked arch. arched_ceiling.blend (449 KB)

[JamFX]

@@Sanctuary

The only problem with this method is that you don’t maintain the correct proportions with the rest of the models. I forgot to mention this limitation I have in my first post. Sorry.

I’m doing ceilings for a 6 blender units wide corridor, and using wall “tiles” 4 BU long. So the main corridor ceiling piece is 6x4, and 3 high. For the corners I’ll go with 6x6, because it’s easier to work with and it looks good overall.

But as you rotate that initial half circle the dimentions shrink… thus my problem gets complicated. I’ll probably have to use other methods unless there’s some way to scale it precisely to the correct proportions. Snapping doesn’t usually work that well with scaling…

dont simply rotate the original circle section. use the shear tool instaed shift/ctrl/alt/ s that should solve the proportion issue.

I meant you to duplicate (shift D) the edgeloop in picture2 after you select it. then move on to pic 3.

[pappy]

Perhaps the “pipe joint” add-on would work.

Add a cross joint pipe and adjust it to the correct Blender units.

From there you can simplify with deleted vertices and the mirror modifier.

Some loop-cuts and fine tuning of the one corner you might need to edit and your done.

Attachments

pipe_test.blend (481 KB)

[Sanctuary]

@@Sanctuary

The only problem with this method is that you don’t maintain the correct proportions with the rest of the models. I forgot to mention this limitation I have in my first post. Sorry.

I’m doing ceilings for a 6 blender units wide corridor, and using wall “tiles” 4 BU long. So the main corridor ceiling piece is 6x4, and 3 high. For the corners I’ll go with 6x6, because it’s easier to work with and it looks good overall.

You can rescale your model with S and pressing SHIFT+the axis you want to exclude from the scaling.
Enable before that the snapping tool and set it to increment and you’ll be able to rescale your model following the blender units of the grid, matching then easily the original proportions if they’re in exact BU .

The shear solution is better though as it does not require the extra step of rescaling in the end

[eppo]

Knife tool - keystrokes kzc 3 times on a half cylinder top view: 1st time across to get two starting points, 2 times move mouse slightly diagonally and cut will constraint to 45 deg. Delete some faces, extrude vertices.

[Skaruts]

You can rescale your model with S and pressing SHIFT+the axis you want to exclude from the scaling.
Enable before that the snapping tool and set it to increment and you’ll be able to rescale your model following the blender units of the grid, matching then easily the original proportions if they’re in exact BU .

The shear solution is better though as it does not require the extra step of rescaling in the end

Unfortunately increments don’t make the verts snap to the grid, only to grid sized increments (as far as I know). That is, if the vertex you’re moving or scaling is off the grid, it will stay off of it as you move/scale it. Which is why I tend to avoid rotating and scaling things when proportions need to be exact or when I need vertices to stay on the grid (because they take vertices off of the grid). You can bring a vertex to the grid with the help of other vertices or the 3D cursor, but that’s hard to do with many vertices and complex shapes.

The Shear tool works well indeed, though I already made my domes with shrinkwrap. At this point I’m only testing other possibilities. But Shearing solves the proportions problem with that method, actually. Those are two good (fast) ways of doing it, considering the limitations I have in this case.

The knife tool is something I rarely ever used, to be honest. I don’t even know the hotkey… K? I guess it was that. I may give it a try.

Another thing I tried was connecting vertices using J to make the cross-loops, but it doesn’t work, the loops it creates are rounded (when viewed from the top). Well, with some adjustments it might work… I suppose.

Thanks everyone for all the suggestions. Keep them coming if there’s more. I always like to know more.

[JamFX]

j is to join verts across a face, you need f to fill an edge.

[Skaruts]

Yes. I meant it as in to replicate what you did with the shear tool. I had to create 15 edge loops (to make it even with my 16 sided half cylinder) so that I had enough vertices to connect it all the way from one end to the diagonally opposite end. But the result is a “round” loop, so it requires more work than both the shear tool and the shrinkwrap modifier.

Basically it makes what is on the top, while shear and shrinkwrap give me the bottom one:

[eppo]

I don’t even know the hotkey… K?

It’s KZC in a sequence, then move mouse to snap or just cut something. Tooltip is on the status line, down.
Result will be like your orange, 1st.

[Skaruts]

Oh, I hadn’t noticed you were mentioning the keys before. :S Thanks.

[Skaruts]

@@Sanctuary

Turns out I was wrong about the scaling stuff. You can actually scale using the snapping tool (to vertex), using some helper vertices or other models that may be in the scene. And it works quite well. Somehow I had the idea that it wouldn’t work, perhaps this comes from the times of blender 2.4x where sometimes things messed up, and maybe I didn’t try it out again in 2.5x+.

Anyway, I tried that and it worked wonderfully. It requires just a little bit more work than shrinkwrap and shear, but not really so much that makes it tedious.

After I made the quarter-dome I created a separate vertex, snapped it to grid (selection to grid), then snapped the model’s corner to that vertex. That aligned that corner to the grid just fine. I then placed the cursor at that corner and created another helper vertex exactly 6 BUs away from the cursor, horizontally, and scaled the whole geometry so that I snapped the second corner to the second helper vertex (sometimes this doesn’t work if the vertex is too far from the geometry you’re scaling, in that case you can scale it to reduce their distance and then scale again and snap should work).

Then all that was left was the converging point (the V-shape), I placed another helper vertex at the correct spot, aligned to the grid, placed the cursor at one of the vertices on the side opposite to the V-shape’s point (anywhere will do, as long as it’s on that side) and the V-shape scaled perfectly away from the cursor and snapped to the helper vertex.

So that method is actually viable even without the shear tool, after all.
Cheers.

[Skaruts]

eppo, I was trying the knife tool but I’m having trouble making it cut correctly. Everything works as intended (as you described), except the snapping. When I click it it seems like it snaps to the vertex, and then it seems to snap the opposite side’s vertex too, but after confirming the cut and zooming in I see that the cut ends up on the edges, not on the corner vertices (creating two new vertices, one on each end).

(I’m doing that from the top view)

Any ideas on what may be going wrong here?

EDIT: It worked well when I created a loop in the center and started cutting from the center-most vertex towards the corners. Can it happen that the knife tool has trouble snapping to vertices if an edge is partially in their way? Seems like something like that was the case.