Recalculating Normals
Normals may have to be recomputed when they are either missing or incorrectly imported.
Tip
Display the normals for a selected surface by ticking the Normals option in the Display box of the Mapping sidebar tab.
Reverse Normals: reverses the normals for the selected surface.
 Results of applying the Recompute normals function with a threshold angle of 85° on a box. |  Results of applying the Recompute normals function with a threshold angle of 95° on a box. |