UV wrong unwrap after changing object origin #43627

New Issue

Dorothy · 2015-02-11T09:09:18+01:00

Dorothy commented

2015-02-11 09:09:18 +01:00

System Information
Windowns 8.1 - nVidia GTX 660

Blender Version
Broken: 2.73a

Short description of error
Changing object origin result incorrect UV unwrap.

Exact steps for others to reproduce the error

create a cube
modify dimensions z=0.5, x,y=10
uv unwrap -> correct
modify object origin
uv unwarp -> incorrect

wrong_uv.blend

Also, when UV unwrap, changing island margin values result different shapes in in UV islands, not scaled, distorted on x or y.

**System Information** Windowns 8.1 - nVidia GTX 660 **Blender Version** Broken: 2.73a **Short description of error** Changing object origin result incorrect UV unwrap. **Exact steps for others to reproduce the error** - create a cube - modify dimensions z=0.5, x,y=10 - uv unwrap -> correct - modify object origin - uv unwarp -> incorrect [wrong_uv.blend](https://archive.blender.org/developer/F142423/wrong_uv.blend) Also, when UV unwrap, changing island margin values result different shapes in in UV islands, not scaled, distorted on x or y.

Dorothy commented

2015-02-11 09:09:18 +01:00

Changed status to: 'Open'

Dorothy commented

2015-02-11 09:09:18 +01:00

Added subscriber: @Dorothy

Dorothy commented

2015-02-11 12:11:41 +01:00

forgot to add one step, after changing dimensions, I've apply rotation and scale.

full steps again here (sorry i did not find a way to modify original post):

create a cube
modify dimensions z=0.5, x,y=10
apply object rotation and scale
uv unwrap -> correct
modify object origin
uv unwarp -> incorrect

forgot to add one step, after changing dimensions, I've apply rotation and scale. full steps again here (sorry i did not find a way to modify original post): - create a cube - modify dimensions z=0.5, x,y=10 - apply object rotation and scale - uv unwrap -> correct - modify object origin - uv unwarp -> incorrect

NikoLeopold commented

2015-02-11 15:55:25 +01:00

Added subscriber: @NikoLeopold

NikoLeopold commented

2015-02-11 15:55:25 +01:00

i guess you used Smart UV Project?
by 'incorrect' you mean different from the last projection?

obviously Smart UV Project is not able to ensure the exact same UV map layout for every configuration of the object. i am not sure if that is considered a bug though.

about the distortion with increased island margin: it seems its just enforcing the island margin, without trying to presevere a perfect orthogonal projection, since thats not being done for every face anyway when the angle angle limit is at a reasonable size. i think it is trying to optimize the use of the uv map space? im really not sure, but im not sure if thats considered a bug either.

anyway, someone more experienced in this module will have to tell.

i guess you used Smart UV Project? by 'incorrect' you mean different from the last projection? obviously Smart UV Project is not able to ensure the exact same UV map layout for every configuration of the object. i am not sure if that is considered a bug though. about the distortion with increased island margin: it seems its just enforcing the island margin, without trying to presevere a perfect orthogonal projection, since thats not being done for every face anyway when the angle angle limit is at a reasonable size. i think it is trying to optimize the use of the uv map space? im really not sure, but im not sure if thats considered a bug either. anyway, someone more experienced in this module will have to tell.

Julian Eisel commented

2015-02-11 16:13:38 +01:00

Added subscribers: @mont29, @JulianEisel

Julian Eisel commented

2015-02-11 16:13:38 +01:00

@mont29 what would you say here? Is this expected?

Dorothy commented

2015-02-11 16:32:16 +01:00

yes, I am talkin about Smart UV Project.

And this is a bug, a perfect square should not produce a rectangle UV.

yes, I am talkin about Smart UV Project. And this is a bug, a perfect square should not produce a rectangle UV.

Julian Eisel commented

2015-02-11 16:43:56 +01:00

And this is a bug, a perfect square should not produce a rectangle UV.

That depends on the method you use. Every method uses a different algorithm using different conditions, parameters, ... So not every method brings the same result!

>And this is a bug, a perfect square should not produce a rectangle UV. That depends on the method you use. Every method uses a different algorithm using different conditions, parameters, ... So not every method brings the same result!

Dorothy commented

2015-02-11 17:01:22 +01:00

With all respect, please ask someone who work on UV unwrap about this bug report, I am sure this is a major bug, if you put test checkers on wrong uv you get distorted texture, incorrect mapping.

Greg Zaal commented

2015-02-12 08:30:29 +01:00

Added subscriber: @GregZaal

Campbell Barton commented

2015-03-11 09:07:32 +01:00

Added subscriber: @ideasman42

Campbell Barton commented

2015-03-11 09:07:32 +01:00

Looking into this, I can't redo the problem with the change in origin giving the incorrect UV layout.

Can you show an image of whats considered correct & incorrect?

Looking into this, I can't redo the problem with the change in origin giving the *incorrect* UV layout. Can you show an image of whats considered correct & incorrect?

Sergey Sharybin commented

2015-03-17 11:01:10 +01:00

Changed status from 'Open' to: 'Archived'

Sergey Sharybin closed this issue

2015-03-17 11:01:10 +01:00

Sergey Sharybin self-assigned this 2015-03-17 11:01:10 +01:00

Sergey Sharybin commented

2015-03-17 11:01:10 +01:00

A week without reply. Due to the policy of the tracker archiving the report for until requested information is provided.

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UV wrong unwrap after changing object origin #43627