Activate this option to unlock geometry normals and force Maya to re-compute the edge continuity.
When you disable the Unlock Normals option, Maya imports the locked geometry normals as they were represented by the application that generated the FBX file.
Maya fully smooth or faceted geometry
If you activate the Unlock Normals option, the object imports with unlocked normals.
If you then unlock the normals faceted edges may appear. This occurs when importing from 3ds Max. If this happens, select the object in Maya and apply the Maya soften edge function to smooth the object.
If you disable Unlock Normals, the object imports with the correct look and the normals will be unlocked.
Maya combination of soft and hard edges
With the Unlock Normals option activated, the object imports correctly with its normals locked. If you intend to deform this geometry you must to unlock the normals, but if you do this the object becomes hard edged in Maya.
Re-import the FBX file with the Unlock Normals option activated to resolve this issue.
If you disable the Unlock Normals options, the object imports correctly with unlocked normals.
When you activate Unlock Normals, Deformed geometry always imports unlocked. The unlock function does not apply in this case.
If you do not have the Unlock Normals option activated, deformed geometry imports unlocked. The unlock function does not apply in this case.
If you activate Unlock Normals, objects imported with smooth meshes import with unlocked normals
If you disable the Unlock Normals option, the normals of objects with smooth meshes import locked.
