Regression: Normal Edit modifier screws up UVs #110471
toggling visibility of normal edit modifier broke the UV
Steps to Reproduce
- Start a new project
- Add image texture on the Cube mateiral
- Turn on auto-smooth normals from the mesh data tab
- Add the Normal Edit modifier to the mesh.
Some of my meshes broke permanently and toggling on or even removing the modifier doesn't fix the UVs.
Broken: 3.6.1, 4.0.0a 2023-07-25
Attached is a .blend for reproducing with a default cube set to a color grid texture.
When the NormalEdit modifier is enabled and then disabled, the UVs mess up. Though enabling and disabling the modifier a second time appears to restore the UVs back to their original state.
The issue appears to be related to the automatic flipping of polygons when their normals do not match their resultant split normals because the issue no longer occurs when Lock Polygon Normals (the lock icon to the right of Mix>Max Angle) is enabled. Toggling Lock Polygon Normals on and off has the same effect as enabling and disabling the modifier.
The issue can also be observed with the Radial mode of the modifier if the Target Object is moved outside of the default cube or if the cube's polygons are flipped to face inwards.
While the modifier is enabled, moving the Target Object around will repeatedly mess up the UVs, restore them, mess them up again etc.
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