scaled object, mirror, applay scale -> result do have a unexpected face orientation #92366

New Issue

Jan · 2021-10-20T13:20:53+02:00

Jan commented

2021-10-20 13:20:53 +02:00

{F11322410}System Information
Operating system: Linux-5.13.19-2-MANJARO-x86_64-with-glibc2.33 64 Bits
Graphics card: NVIDIA GeForce GTX 1070 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 470.63.01

Blender Version
Broken: version: 2.93.5, branch: makepkg (modified), commit date: 2021-10-05 12:04, hash: a791bdabd0
Worked: (newest version of Blender that worked as expected)

Short description of error
[Please fill out a short description of the error here]
Mirroring a scaled object and apply the scale after mirroring. The apply scale flip also the faceorientation. A untouched faceorientation is expected, cause only the scale is to apply, not a apply mirro faceorientation.

Exact steps for others to reproduce the error
[Please describe the exact steps needed to reproduce the issue]
[Based on the default startup or an attached .blend file (as simple as possible)]

Start with default settings.
delete cam and light,
Viewport overlays -> check the Faceorientation field in the menu
(I've done this for you in the uploaded blend file. It's needed to see what is not expected.)

click on cube

press s (scale cube in my case)
~x1.5
~y1.5
~z1.5
menu Object -> Mirro -> x Local -> click on cube (the cube is mirrored now)
(Notice the faces are in the expected orientation, everything is ok)
press shift +a -> press s (to Apply scale,)
(Notice the faces do change flip the orientation. This is not like expected, i do apply scale and not the faceorientation to the object.)

Please note the face orientation is flipped xyz local or global mirroring over the main menu bar after apply scale i do not test other apply possibilities.

Thank you for the very cool blender program.
Have a nice day
Jan

{[F11322410](https://archive.blender.org/developer/F11322410/mirrofaceflip.blend)}**System Information** Operating system: Linux-5.13.19-2-MANJARO-x86_64-with-glibc2.33 64 Bits Graphics card: NVIDIA GeForce GTX 1070 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 470.63.01 **Blender Version** Broken: version: 2.93.5, branch: makepkg (modified), commit date: 2021-10-05 12:04, hash: `a791bdabd0` Worked: (newest version of Blender that worked as expected) **Short description of error** [Please fill out a short description of the error here] Mirroring a scaled object and apply the scale after mirroring. The apply scale flip also the faceorientation. A untouched faceorientation is expected, cause only the scale is to apply, not a apply mirro faceorientation. **Exact steps for others to reproduce the error** [Please describe the exact steps needed to reproduce the issue] [Based on the default startup or an attached .blend file (as simple as possible)] Start with default settings. delete cam and light, Viewport overlays -> check the Faceorientation field in the menu (I've done this for you in the uploaded blend file. It's needed to see what is not expected.) click on cube - > press **s** (scale cube in my case) ~x1.5 ~y1.5 ~z1.5 - >menu Object -> Mirro -> x Local -> click on cube (the cube is mirrored now) (Notice the faces are in the expected orientation, everything is ok) - > press **shift +a** -> press **s** (to Apply scale,) (Notice the faces do change flip the orientation. This is not like expected, i do apply scale and not the faceorientation to the object.) Please note the face orientation is flipped xyz local or global mirroring over the main menu bar after apply scale i do not test other apply possibilities. Thank you for the very cool blender program. Have a nice day Jan

Jan commented

2021-10-20 13:20:53 +02:00

Added subscriber: @de_bugger

Philipp Oeser commented

2021-10-20 15:24:48 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-10-20 15:24:48 +02:00

Hi and thx for the report!

This has come up quite often before (but was never considered a bug (it is basically the same as applying scale on a negative scaled object):

#35293 (When you mirror a mesh the tool flips the normals.)
#37652 (Inverted normals with negative scaling)
#39150 (Mirroring mesh inverts face normals)
#82228 (What could cause Mirrored Objects's calculated loop_triangles to have different normals)
#78512 (Mirroring in object mode screws up normals)

So for now, you have to flip afterwards (or use other stuff mentioned in the other reports).

This could be changed of course, but the issue reported here is a request for modified/improved behavior and not a bug in current behavior. Closing as this bug tracker is only for bugs and errors.
For user requests and feedback, please use other channels: https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests
For more information on why this isn't considered a bug, visit: https://wiki.blender.org/wiki/Reference/Not_a_bug

Hi and thx for the report! This has come up quite often before (but was never considered a bug (it is basically the same as applying scale on a negative scaled object): - #35293 (When you mirror a mesh the tool flips the normals.) - #37652 (Inverted normals with negative scaling) - #39150 (Mirroring mesh inverts face normals) - #82228 (What could cause Mirrored Objects's calculated loop_triangles to have different normals) - #78512 (Mirroring in object mode screws up normals) So for now, you have to flip afterwards (or use other stuff mentioned in the other reports). This could be changed of course, but the issue reported here is a request for modified/improved behavior and not a bug in current behavior. Closing as this bug tracker is only for bugs and errors. For user requests and feedback, please use other channels: https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests For more information on why this isn't considered a bug, visit: https://wiki.blender.org/wiki/Reference/Not_a_bug

Philipp Oeser commented

2021-10-20 15:24:59 +02:00

Closed as duplicate of #78512

Philipp Oeser closed this issue

2021-10-20 15:24:59 +02:00

Jan commented

2021-10-21 13:13:40 +02:00

Hi Philipp,
thx for your fast replay. Yes, it's easy to fix with a flip. If you don't know the workflow first apply and use the mirror. If this happen with many more than a hand full and the work goes on. At the end you have a inconsistent data set. Isn't it a pitfall?

This is not a bug - accept. What about the documentation. Isn't it a missing information?

Your report list shows, I'm not the only one. I don't want to now how many artist trap into and do not report a bug. It waste your time and dos not help artists. For myself and case, I do expect note here
https://docs.blender.org/manual/en/2.93/scene_layout/object/editing/mirror.html?highlight=mirro%20object
(Before report a bug, RTFM :)

I would like to make a proposal to add some notes to the documentation. A link to a pitfall page cause this effect appears also at some other tools. In myimagination is the pitfallpage a page where you can find unexpected things and how to avoid, solve and find correct workflows for surprising effects.

regards Jan

Hi Philipp, thx for your fast replay. Yes, it's easy to fix with a flip. If you don't know the workflow first apply and use the mirror. If this happen with many more than a hand full and the work goes on. At the end you have a inconsistent data set. Isn't it a pitfall? This is not a bug - accept. What about the documentation. Isn't it a missing information? Your report list shows, I'm not the only one. I don't want to now how many artist trap into and do not report a bug. It waste your time and dos not help artists. For myself and case, I do expect note here https://docs.blender.org/manual/en/2.93/scene_layout/object/editing/mirror.html?highlight=mirro%20object (Before report a bug, RTFM :) I would like to make a proposal to add some notes to the documentation. A link to a pitfall page cause this effect appears also at some other tools. In myimagination is the pitfallpage a page where you can find unexpected things and how to avoid, solve and find correct workflows for surprising effects. regards Jan

Philipp Oeser commented

2021-10-21 13:41:00 +02:00

Added subscriber: @Blendify

Philipp Oeser commented

2021-10-21 13:41:00 +02:00

@Blendify might be interested in adding that to the documentation

Sign in to join this conversation.

No Label

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

scaled object, mirror, applay scale -> result do have a unexpected face orientation #92366