After finding that the normal direction is reversed, it is recommended to switch to the edit mode and select all vertices directly, select "Mesh" - "Normal" to reverse the normal direction.
Before flipping,
select all vertices in edit mode,
select flip normals in the mesh tab,
and solve at the speed of light
The following is me who was ignorantly looking for a solution for a long time when I updated for the first time
Recently, I am following the tutorial of Master Zac to learn sculpture and become a poop modeling artist.
When I was doing the final preparations before sculpting, I found that after applying scaling, the normal of the object would be completely reversed.
The original look
It feels like the direction of the normals is completely reversed after applying the scaling.
After verification, it was found to be a problem with the scaling factor:
the current scaling factors are all negative values,
adjust them to positive values before applying scaling, and
the problem is solved