Boolean Ops--worthless?

I want to make a small hole in the side of a sphere for an empty eyesocket. I attempted this using another smaller sphere and trying to do a Boolean differance. This didn’t work at all. So…how can I make a nice round hold in the side of a sphere?

How about creating a UV sphere and cutting the end off.

This operation is dependant on the order you select the objects, try to select them backwards.

Because I don’t want the hole in the middle of the sphere.

Hi, I may be missing something here. But if you cut off the top/bottom then rotate the sphere so the hole is where you want it, then what is the difference.

Unless of course, the sphere has already been scaled in a non-uniform manner.

Well, I still need ~two holes. (For two eyesockets) So that still wouldn’t work.

Ahh, I see nuff said :stuck_out_tongue:

How about…

Create a small sphere and cut off one side so you have a nice round hollow.
Cut a hole in the side of the sphere just a bit larger than the largest edge loop of the smaller sphere.
Insert the smaller sphere in the hole so that it’s nicely lined up.

Use lofting script to join the edge loop of the smaller sphere with the hole cut into the larger sphere.

Or - more painstakingly - weld the vertices of one to the verticies of the other.

Alternatively, cut a whole in the sphere and use extrude and scale to make a roughly spherical indent.

Either of those methods sound vaguely interesting?


I don’t know if this is what you want, but if you use subdivision surfaces, or have enough vertices you can get a pretty smooth hole by:

  1. selecting the vertices where you want your hole to be (preferably square shaped)
  2. save this selection in the edit buttons
  3. delete all the inner faces
  4. select the hole with the saved selection
  5. Shift+S, to get the cursor right in the middle of the hole
  6. to sphere, in the edit buttons

It will be “spherized” more precise if you put the cursor at the place of the most inner vertice you had in the hole.

That sounds about what I want—but HOW do I cut a hole?

I think he means that you should delete some vertices from the big sphere to have a square-shaped hole. Then you make it circular by snapping the vertices to those of the sliced sphere.

I think, then, that my copy of Blender is corrupt…because when I delete the vertices…nothing happens.

If I want to cut a hole, depending on where I want it, I either delete verticies - if there are identifiable, circular rings exactly where I want them to be, or I use the knife tool.

If I use the knife tool, I put the secondary (smaller) sphere about where it’s going to end up and then I cut around it.

Once I’ve finished, I select the verticies from the circle I’ve created with the knife tool and then I hit P and separate the vertices from the sphere. Then I can select the part that I’ve just separated and delete it.

I hope that makes sense.


I have made several requests for better boolean operations in Blender and have received basically nothing in responses.

I do that they are being worked on and that it will not be added to blender for a while anyway.

I have used booleans in Lightwave and they just absolutley rock in that app. Makes very nice clean cuts. Hopefully Blender’s booleans can get to that level.

For now, just don’t even use them, IMO.


Hmmmm - just trying my solution is a bit fiddly.
You might need to work a bit to get an even and smooth progression from the outer sphere to the inner sphere.

It might be better to avoid using the knife tool and to take a different approach, like removing the verticies until you have a square hold, create a half sphere with the same number of vertices around the edge as around the edge of the square hole you’ve made and then attach the two.

I might have a bit more of a play and see if it works.


OK - so I tried it out a little.

So far the best I’ve got is to select verticies from the larger sphere and deleted them to make a hole appropriately the right size.

Then I create the half-sphere but not with the same number of vertices as the edge of the hole. It doesn’t give a great final result.

Instead I use the same number of verticies as the edge of the square I just deleted from the larger sphere.

I place the half sphere and then I manually make the faces so that the face loop of the larger sphere doesn’t end up being broken (as much as possible).

It’s not perfect but it seems to give a much better moulded look than the other methods I experimented with. Let me know if you don’t know what I’m talking about because this kind of stuff is hard to explain. :smiley:


Read this thread… there’s a link to a script tuinbels wrote there as well…

The script is great. It’s basically the knife function with a difference. However, you still end up with the same knifelike problems. Messy polygons/triangles that destroy the effect as soon as you turn on subsurfs.

The problem with modelling really smooth objects is that if you aren’t really careful with the form of your polygons you loose the smoothness altogether.
And the problem with some of the fancier modelling scripts and functions is that they just can’t be careful enough.

It is a pretty fine script however.


It may be a little out of topic here, but have you tried using Wings 3D for this? You could create a sphere in wings, select the face(s) you want to cut a round hole , backspace to dissolve them into a single face then smooth repeatedly until it degenerates into a fairly round face. The latest version of Blender imports wings file quite painlessly. I wouldn’t expect a perfectly round hole, but close enough.

You know proportional editing doesn’t work too horribly for this situation as long as you keep the subsurf up to 3 it looks fairly smooth.