Convert surfaces into a shell object

1. Make sure the surfaces are all facing outward.(See Change the orientation of surfaces for more information.)
2. Pick the surfaces you want to combine into a shell. The surfaces must together define a closed space with no gaps.
3. Choose Surface Edit > Stitch > Shell Stitch.

   The prompt line provides feedback on the result of the operation. For example: “Created 2 shells with 0 boundaries (0 non-manifold).”

   If some boundaries are left open, small red arrows point to them.

   Note

   Depending on how you set the options, a shell may not match the original surfaces exactly. In this case, unstitching will not produce surfaces that match the originals exactly either.

Convert a shell object into its separate surfaces

1. Pick the shell object.
2. Choose Surface Edit > Stitch > Shell Unstitch.

What if...?

I can’t make a shell object because of gaps between the surfaces?

• You can use the Align tool to make the surface edges match exactly.

See Align curves and surfaces with continuity

• You can change the tolerance governing how close surface edges must be. In the option box, turn off Use construction options and set the Tolerance value.

I can’t stitch surfaces together again after scaling them?

If you stitch an object, then scale it, then unstitch it, you may not be able to re-stitch the object. This is because the scaling operation can increase the gaps between surfaces beyond the current tolerances.