sink a half sphere into a cube.

(anon125) #1

maybe cos the normals are round the wrong way but i cannot sink the bowl into the cube.
yes i selected both - W -union.
didn’t work

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(Orinoco) #2

Default sphere, default cube? Booleans don’t work (well) when the vert count in the two objects is too different. If you used the defaults, try subdividing the cube a couple times first.

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(anon125) #3

dept of weird still rules.
how the heck do i do this! in 2.42

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(Orinoco) #4

I have not got a clue what you’re trying to show me with those images.

Are you trying to get a hemisphere attached to the surface of a cube? Or a hemispherical depression in a cube? There’s probably a way to model what you’re trying to model, but you’ll have to describe what that is.

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(Krice) #5

If booleans don’t work well you might want to start from the hardest part of the object. In this case begin from the half of the sphere and extrude & adjust the edges to create the top part of the box. Then model the remaining box. It’s “model the hole first” -rule.

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(anon125) #6

hemispherical depression in a cube is what i am trying to do.
i rotated the normals to point inward on the sphere

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(Orinoco) #7

Start with the hemisphere. Extrude the edge and scale it outward. Square off the new edge by selecting 1/4 of the vertices at a time, and scale them to zero along the appropriate axis [eg: s,x,zero]. use the squared off edge to extrude the rest of the box.

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(anon125) #8

that would work but i am trying to sink door handles into an aready built car.

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(DGEbel) #9

Any door handles I’ve seen are not perfect spherical indentations, more of a depression. There’s several ways you could do it by vertex juggling. As you’ve seen booleans are a failing of Blender.
0. First though, you’ll probably have to subdivide to increase the vertex count.
You could also leave your sphere there as a reference.

  1. Just go into edit mode, grap vertices that will be the most “depressed”, then
    a) switch proportional mode on (o-key) and use the +/- keys to adjust the field strength, as you drag them back into the body.
    Hmm… alt-s-key/shrink might be good here but I don’t remember it working in tandem with proportional mode.
    b). or Extrude into the body several times. Or if your subdivision is high enough, once might be enough :slight_smile:
    c) do both
  2. You will then likely want to select & smooth the sunken vertices. You might try using the “to sphere” option at 50%. Not really sure how that works, especially for a sunken surface. Might have to view it from “inside” the door, I vaguely recall the sphere curving away from the viewpoint.
    Oh, and especially when smoothing, unselect the “bottom” vertices to keep them at the depth you want.
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(grasshopper) #10

You can also use the retopo tool. I certainly wouldn’t recommend it for a sphere, but maybe for more complicated shapes.

Here’s a picture of a torus I sunk into a plane using retopo.


Slice the torus with another plane at the depth you want it “sunk”. Subdivide and/or multires the plane to get enough vertices. Position above the torus and apply retopo to all vertices. It projects the vertices down onto the torus and second plane. As you can see, the geometry is pretty bad - there are several visible artefacts around the edge of the impression and this is with some heavy smoothing modifier usage applied! That’s because retopo stretches the edges too much when the angle of the surface it’s mapping onto is high (because the in-plane coordinates of the vertices are locked to a grid). Hence, I don’t recommend it with a sphere, but just in case this comes in handy for something else…

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(DGEbel) #11

That reminds me of another old technique that works well for complicated shapes if the mesh has a high enough resolution:

  • make and an image corresponding to the height of the different surface features (bump-map)
  • apply the texture to your mesh and position it to the exact position (and scale) where you want the mesh modified
  • in mesh Edit mode, on the Modelling tools (F9) panel, select the vertices you want to affect and click the NOISE button several times. This will apply the relative value of the texture to the actual mesh, deforming it to match the bump map. The more times you click it, the more the mesh is affected
  • you can remove the texture now, and probably want to
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