Sculpt mode, Symmetry, and the 'H' hotkey

Question

I'm sculpting a human model using symmetry, so I only had to sculpt one side. When I got to the legs I was having trouble sculpting the muscles on the inner leg I zoomed out, hit H, and hid half the model for convenience. Once I had finished sculpting I hit AltH to bring back the missing half, but none of the work I had done transferred onto the other side. Is there any way I can fix this?

Answer 1

Dyntopo has a symmetrize button which will symmetrize your geometry on any axis.

If you pick the wrong direction you can undo and choose another.

While you don't need to do any sculpting in dyntopo to use this, you do need to enable it, which means you can loose UV's and vertex colours that can normally be lost when enabling dyntopo.

Answer 2

If you haven't already put much work on the formally hidden side, I'd go with the brute force method.

1. Make a copy of your file.
2. Create a cube that covers half of your mesh completely.
3. Place it over the "bad" half of your model.
4. Use a boolean modifier with union or difference (whichever delivers no error) and apply it.
5. Delete the cube and check your mesh for leftovers (sometimes the boolean modifier produces a big ngon at the intersection).
6. Use a Mirror Modifier with Merge and Clipping (forgot that one in the picture below) and apply it.