Intersecting two objects... (how to cut a hole in a sphere)

Support Modeling
1

I want to make what is essentially a bead. A sphere with a hole in it that a cord can pass through. This is going to be printed in plastic on a 3D printer. I know how to make a sphere, and I know how to make a cylinder, but I don’t know how to make a cylindrical hole in a sphere. Can someone walk me through that?

2

There are a few ways, here’s a couple.
Use a boolean modifier to cut the cylinder from the sphere. (make sure to run the cylinder through the polars of the sphere for clean geometry)
The other way would be to delete the caps and any aditional faces to get the desired hole size (use edge slide if needed (Ctrl+E)), then create faces by selecting 2 neighboring points on both holes and press F to create a face, repeat till the inside of the hole is filled.

3

I added a circle (with ‘Fill’ enabled), cut a hole in it with the knife tool (K), and selected “Midpoints” in the operator menu. Then I extruded to the appropriate length, deleted the middle faces on the ends, switched to edge select mode and made the faces along the inside.

To finish it off I set the shading to “Smooth” and added a level 3 Subdiv modifier.

Attachments


4

Can you tell me the steps to “use a boolean modifier to cut the cylinder from the sphere”? Thanks! I’m extremely new to this software and 3D modeling in general, so be patient with me…

5

That looks more like a tube/barrel than a sphere… what I need is a true sphere.

6

Just last week I needed to do the same thing. Here’s a great tutorial:

Good Luck!

7

Scale along Y axis :wink: Boolean modifier is probably easier though, didn’t think of that before.

8
  1. Add UV sphere and enter edit mode (Tab).
  2. Remove caps.
  3. Select both edges of resulting holes.
  4. w->LoopTools->Bridge. Select all(A, A), w->remove doubles, Ctrl-N, w->shade smooth. (Requires use of Loop-tools addon, may be buggy.)
    4b. Alternatively, set snapping to vertex, select one of the edge loops, E, Z, press and hold Ctrl, mouse over one of the vertices of the other loop, click, release Ctrl, Select all(A, A), w->remove doubles, Ctrl-N, w->shade smooth. (Does not require addons)
  5. Add two edge loops on inside of tunnel (Ctrl-R, mousewheel to increase iterations to two).
  6. Make sure both are selected.
  7. S, Z, scale up almost up to the edge, but not all the way.
  8. Exit edit mode (Tab)
  9. Add Subdivision Surface modifier.

Result:

http://i.imgur.com/P2t18.png
P2t18.png567×540