Pretty simple but can't work it out: half a sphere

Hello,

I am trying to make half a sphere and I can’t work out a way to do it. I guess I could revolve an arc around an axis but I imagine there is much more simple than that!

The problem is that when I try to take a sphere and intersect half with a cube it makes ugly “artifacts”.

Any idea?

thanks!

Could you add a sphere mesh with twice the number of rings or loops and delete half of it so it has the right count?

I am not sure I understand exactly, but I should have said that I would like a closed half sphere. I am not sure wether this would keep it “closed”.
Would it?

If there was a way of selecting a number of points and aligning them on the same plane I guess that would make it … I know how to do that with adobe illustrator but … well :slight_smile:

Lets see, here’s how to do it->

In a straight on view (doesn’t really matter which, I just used the default top view (numpad-7)) Press Space->Mesh->UVSphere

Give it 12 rings and 12 segments (for this example, you of course can vary it).

You should be able to select half the sphere with box-select (b-key). Be in wireframe mode to do this (z-key).

Delete these vertices (x-key-> Vertices).

Now box select (b-key) the lower vertices (the open part of the half-sphere). Then press shift-f to beauty fill the open half of the sphere. You could also manually select vertices and fill with f-key.

Thanks forte! … I managed to do it :slight_smile: - but now there is another problem: the way it fills results in irregularities when I do a subsurf. Do you have any idea how to remove that?

With those bottom vertices still selected (or re-selected) press alt-j. This will join the triangles (what creates nasty subsurf) into quads. If it doesn’t join all of them, then manually select the few remaining triangles and press alt-j to join them.

That’s great! Thanks :smiley:

Select the bottom loop (open one) and Extrude then Scale it in to zero so the extruded verts all end up in the center of the flat side. Then remove doubles.
Or, select the bottom half of a UV Spbere, hit period-key (Pivot Cursor), S (scale) Z (axis) and 0 (zero) to the Cursor.

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Thank Fligh, that looks pretty good too :smiley:

I learned very basic useful tricks thanks guys!

Yet another option. :slight_smile: Select all the verts to merge, and then hit ALT + M, then center.

ok, I feel like I’m jumping on a dogpile here but a slight addendum to what fligh said.

extrude->scale to a point makes tris too, and will make some ringing artifacts with subsurf. instead, you can extrude->scale almost, but not all the way to the center (.7 or so) and then extrude scale to the center and remdoubles.

this puts the tris on a flat plane, where the bordering faces are also coplanar so you won’t see artifacts with subsurf.

Right! I guess that gives me a couple of options :slight_smile: Thanks to all of you guys.