How to Slice Mesh for 3d Printing


I need to slice (and separate) a complex mesh into two meshes, while keeping both parts solid,
for 3d Printing (since it’s too big to be printed in just 1 go).

I’ve tried boolean operations, but sometimes they don’t work properly.

What would be the easiest, more pratical way of doing this?


I don’t want to say that this is the easiest way, but at least it’s a possible way:

  • deselect “Limit selection to visible” in the 3D view menu bar

  • Go to ortho Top Perspective (any other would be as good) by pressing “7” and “5”

  • Select half of the mesh, press “p” to separate the selection from the rest of the object

  • Move the separated part so you can edit it.

  • Select the “border” points/edges manually (this might be the really tedious part, but maybe you can use border select, or Edge Loop) until you have selected the complete loop

  • close the loop by pressing “f”

  • select the newly created face, duplicate it, separte it and join it with the other part of the mesh

  • move it (manually) so that it very, very closely matches the other surface

  • select all and remove doubles, maybe increase the Merging Distance

Booleans, figure out how to make them work. It’s touchy and tricky, but not random.

The Sculpt Tools Addon adds great functionality for operations between selected objects, without the modifier hassle. Put half your model in a cube object, select both, hit Separate. Voila - Model split in two, defined by the cube-geometry.
The same gotchas of the basic Boolean algorithms apply, but trial-and-error becomes much more convenient.

Confirmed to work fine with 2.65a.

For just slicing, the basic Knife tool works fine. There’s instructions in the 3d-view menu how to activate different functions, like “cut through”. Then you can hit V with edge loops selected to separate and move them.

About blackno666’s point “Move the separated part so you can edit it.”… use a numerical value, and it’s easy to move back exactly in place. Easy to forget when shuffling parts around, but very worthwile.