Smart UV project produces wrong, stretched UVs regardless of "Correct Aspect" option state #85194

New Issue

Ludvik Koutny · 2021-01-29T12:38:36+01:00

Ludvik Koutny commented

2021-01-29 12:38:36 +01:00

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 461.09

Blender Version
Broken: version: 2.91.0, branch: master (modified), commit date: 2020-11-25 11:06, hash: b50598bc78
Worked: 2.90.1
Caused by 9296ba8674

Short description of error
Smart UV project feature constantly produces wrong, stretched UVs regardless of the ON/OFF state of "Correct Aspect" option, and regardless of aspect ratio of the texture displayed in the image editor. The failure stems from the fact that aspect ratio of the BaseColor texture is used to distort the UVs of the Smart UV projection regardless if the user wants it or not. This in turn makes it simply impossible to use Blender for UV mapping when any material present of the unwrapped object contains textures of non square aspect ratio. The geometry in the viewport has scale transforms applied, so that is not a source of the issue.

2021-01-29_12-31-19.mp4

Exact steps for others to reproduce the error

Open attached .blend file: UVScaleBug.zip
Select the only object in the scene, and try to unwrap it using Smart UV project
Result: It is not possible to utilize Smart UV project to produce UVs of correct aspect ratio (matching the aspect ratio of the geometry inside 3D view) regardless of the "Correct Aspect" option state
Expected: It is possible to produce UVs matching the aspect ratio of the actual geometry in the 3D view (without any non uniform distortion)

**System Information** Operating system: Windows-10-10.0.19041-SP0 64 Bits Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 461.09 **Blender Version** Broken: version: 2.91.0, branch: master (modified), commit date: 2020-11-25 11:06, hash: `b50598bc78` Worked: 2.90.1 Caused by 9296ba8674 **Short description of error** Smart UV project feature constantly produces wrong, stretched UVs regardless of the ON/OFF state of "Correct Aspect" option, and regardless of aspect ratio of the texture displayed in the image editor. The failure stems from the fact that aspect ratio of the BaseColor texture is used to distort the UVs of the Smart UV projection regardless if the user wants it or not. This in turn makes it simply impossible to use Blender for UV mapping when any material present of the unwrapped object contains textures of non square aspect ratio. The geometry in the viewport has scale transforms applied, so that is not a source of the issue. [2021-01-29_12-31-19.mp4](https://archive.blender.org/developer/F9603820/2021-01-29_12-31-19.mp4) **Exact steps for others to reproduce the error** 1. Open attached .blend file: [UVScaleBug.zip](https://archive.blender.org/developer/F9603828/UVScaleBug.zip) 2. Select the only object in the scene, and try to unwrap it using Smart UV project Result: It is not possible to utilize Smart UV project to produce UVs of correct aspect ratio (matching the aspect ratio of the geometry inside 3D view) regardless of the "Correct Aspect" option state Expected: It is possible to produce UVs matching the aspect ratio of the actual geometry in the 3D view (without any non uniform distortion)

Ludvik Koutny commented

2021-01-29 12:38:36 +01:00

Added subscriber: @Rawalanche

Philipp Oeser commented

2021-01-29 13:25:50 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-01-29 13:25:50 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Philipp Oeser self-assigned this 2021-01-29 13:25:50 +01:00

Philipp Oeser commented

2021-01-29 13:25:50 +01:00

Hm, can confirm there is something wrong with Correct Aspect.

Works fine with the material(s) unlinked.

Will check.

Caused by 9296ba8674 btw.

Hm, can confirm there is something wrong with `Correct Aspect`. Works fine with the material(s) unlinked. Will check. Caused by 9296ba8674 btw.

blender-admin commented

2021-01-29 14:52:48 +01:00

This issue was referenced by d917d7cf94

This issue was referenced by d917d7cf948579f6aee58863f16225ed6e5ec2a0

Philipp Oeser commented

2021-01-29 14:58:29 +01:00

Think this is actually quite important and would be good to have in 2.92 (unless I am really misunderstanding something here), will set to High priority.

Philipp Oeser commented

2021-02-02 09:32:34 +01:00

Changed status from 'Confirmed' to: 'Resolved'

Philipp Oeser closed this issue

2021-02-02 09:32:34 +01:00

Jonathan Hart commented

2021-04-02 03:42:38 +02:00

Added subscriber: @Jonathan-Hart

Jonathan Hart commented

2021-04-02 03:42:38 +02:00

Hello all I believe this might have something to do with the Origins of the mesh creation, when i use the new mesh creation tool, it causes uv distortion when correct aspect is checked, but if i create a very similar mesh without using the quick tools it does NOT distort. I didn't know if this helps =o

jonathan (i'm new here sorry if im not following protocol on posting on REsolved" comments"

Hello all I believe this might have something to do with the Origins of the mesh creation, when i use the new mesh creation tool, it causes uv distortion when correct aspect is checked, but if i create a very similar mesh without using the quick tools it does NOT distort. I didn't know if this helps =o - jonathan (i'm new here sorry if im not following protocol on posting on REsolved" comments"

Thomas Dinges added this to the 2.92 milestone 2023-02-08 16:14:50 +01:00

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Smart UV project produces wrong, stretched UVs regardless of "Correct Aspect" option state #85194