Regression: Normal Edit modifier screws up UVs #110471

New Issue

Moby-Deee · 2023-07-25T19:31:29+02:00

Moby-Deee commented

2023-07-25 19:31:29 +02:00

Broken: 3.6.1
Worked: 3.5
Caused by 7eee378ecc

Shot Description
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.

NormalEditUVsBug3.6.1.blend

Broken: 3.6.1 Worked: 3.5 Caused by 7eee378eccc8f87e1330b9cfea2799928be9d657 **Shot Description** 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. [NormalEditUVsBug3.6.1.blend](https://projects.blender.org/attachments/596d63cc-4dbb-43b1-b341-cf735333e1fb)

bug.jpg

53 KiB

Moby-Deee added the

labels 2023-07-25 19:31:30 +02:00

Pratik Borhade commented

2023-07-26 05:27:20 +02:00

Hi, can you share .blend file with us?

Pratik Borhade added

Status

Needs Information from User

and removed

Status

Needs Triage

labels 2023-07-26 05:27:28 +02:00

Thomas Barlow commented

2023-07-26 07:33:06 +02:00

Broken: 3.6.1, 4.0.0a 2023-07-25 aebc743bf1c7
Worked: 3.5.1

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.

Broken: 3.6.1, 4.0.0a 2023-07-25 `aebc743bf1c7` Worked: 3.5.1 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.

NormalEditUVsBug3.6.1.blend

106 KiB

Pratik Borhade changed title from ~~Normal Edit modifier screws up UVs~~ to Regression: Normal Edit modifier screws up UVs

2023-07-28 08:18:35 +02:00

Pratik Borhade commented

2023-07-28 08:22:27 +02:00

Thanks, can confirm the regression :)

Pratik Borhade added