I took a cube, stretched it, added a number of intermediate edges and adjusted their height to get a humpy top surface.

Now, I want to get a smooth top surface by adding interpolated vertices. The existing edges must not change their position. How do I do this?

FYI: The object will be 3D-printed.



@eromod's hint was the solution.

  • I created a huge ovoid (an icosphere that I compressed on one axis for an additional hump on the other axis),
  • aligned it carefully manually,
  • extended the original top surface in top direction,
  • applied a boolean modifier with "Intersect" operation,
  • and did a bit afterwork on the mesh.

Please leave a comment if there's something I forgot to do proper preparation for rounded edges around the top surface.


  • 2
    $\begingroup$ Could you please clarify what is "huge ovoid" and "intersection modifier" ? Does the latter mean Ctrl+F > Intersection (Knife) ? Also please don't include new question in the answer; ask a new question instead. $\endgroup$
    – Mr Zak
    Aug 3 '16 at 11:26
  • 1
    $\begingroup$ To me, you may have problems with triangles on the lateral faces when printing $\endgroup$
    – lemon
    Aug 3 '16 at 15:28
  • $\begingroup$ Hm, (1) I'm only seeing triangles at the top, (2) the object will be 3D-printed at 0.1 mm with the SLS method (powder + laser) in nylon, which is quite good. So, I can't unterstand what effect you're referring to. $\endgroup$
    – t_w
    Aug 3 '16 at 16:07
  • $\begingroup$ I think the faces will be triangulated. This is not visible in your image here, but enter edit mode, select all the vertice then ctrl+T. I am not a specialist, but I am quite sure the 3D printer will translate it like that. To tell it in other way, lateral faces are big ngons. You may ask about that using another question. $\endgroup$
    – lemon
    Aug 3 '16 at 17:07
  • $\begingroup$ I see what you mean. I hope it gets resolved when rounding the edges around the top surface. $\endgroup$
    – t_w
    Aug 3 '16 at 17:51

hold shift , select the opposing edges of a face, press W and choose subdivide . This will split a face in two.


  • $\begingroup$ I moved all the comments to this chat room, because it was getting quite long. Feel free to keep your discussion going in there. $\endgroup$
    – David
    Aug 3 '16 at 13:02

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.