How to slice a cube using a mesh?

I want to do exactly what ‘Shakespear’ is doing in this video: https://www.youtube.com/watch?v=bzwybr65I9o&t=17m30s

That is, I have imported a mesh (from 3DF Sephr in .obj format) into blender. I now want to turn that flat mesh into a solid object ready for 3D printing.

Shakespeare does this by cutting a cube in half using a mesh. But this operation does not work for me as it does in the video. Actually, what happens for me is what I would expect from a Boolean intersect operation - I just end up with a flat mesh again.

So how can I turn this flat mesh into a ‘solid’ 3D object?

That’s simple boolean operation. Nothing complicated.
Issue here is, that no one can observe your work!
So show it. What you got? Where you stuck at? Best, post your file!

So you would expect that Boolean operation to cut the cube in half - and make the top half disappear as shown in the video?. I believe I am doing the same thing … I have a cube, with a mesh running through its centre. When I perform the Boolean operation, the whole cube disappears and only the intersecting volume remains (which I what I would expect from the term ‘Boolean intersection’ - and from reading the manual: Boolean Intersection Manual Page

Works as expected, see attached file.island.blend (469.0 KB)

Blender 2.79, Make sure to use the carve solver.

Thank you - I see that I was not using the ‘carver’ setting. However, I am still getting an error message when I try to do this. I now suspect that this is becuse the mesh I have has many holes in it. When I select by non-manifold, it shows many highlights. But I don’t know how to repair it … so this probably requires another post. The file is here: https://drive.google.com/file/d/1WvUGOtZr81qQ-7PZqKVrsNqwmvMHgyCw/view?usp=sharing

  • Unapplied scale, ctrl+A -> scale to apply

Finding and fixing non-manifold enough for boolean

  • remove doubles
  • select non-manifold, face select to get the interior faces, delete faces

Fixing the orientation

  • hook the mesh to a new object, select all and ctrl+H
  • reset rotation, alt+R
  • apply hook modifier
  • delete helper empty

Boolean

  • Add a cube, scale
  • apply object scale for the cube
  • boolean intersect with carve solver

JA12, This is amazing! Thank you so much. I worked through your video and it worked perfectly. Not only have I managed to create the model I wanted - but I learnt a lot about the Blender tool in the process. Your generosity in giving up your time for this is much appreciated!