Symmetry editing not working correctly #91026

New Issue

Kit Matthews · 2021-08-29T12:43:05+02:00

Kit Matthews commented

2021-08-29 12:43:05 +02:00

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 471.68

Blender Version
Broken: version: 2.93.1 and 2.93.3 LTS, branch: master, commit date: 2021-06-22 05:57, hash: 1b8d33b18c
Worked: (newest version of Blender that worked as expected)

Short description of error
Using X symmetry Grab or Scale on certain parts of a mesh - leaves an odd, seemingly random assortment of polygons unaffected on the opposite side of the mesh. Eg. massive polygon stretching occurs as random vertexes are left behind.

Exact steps for others to reproduce the error
Turtle broken symmetry.blend

Select turtle,
edit mode,
check that X Symmetry is enabled,
enable Xray view,
select one of the rear feet,
move it,

you will see a bunch of vertices around the nails are left behind every time.
The same occurs for rear feet., left-right or right-left, for scaling moving etc, and Select Mirror.
It is acting as if the mesh is not symmetrical, in some parts, but it appears symmetrical to me and is symmetrical enough to cause z-fighting if i duplicate and mirror a foot.

**System Information** Operating system: Windows-10-10.0.19041-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 3080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 471.68 **Blender Version** Broken: version: 2.93.1 and 2.93.3 LTS, branch: master, commit date: 2021-06-22 05:57, hash: `1b8d33b18c` Worked: (newest version of Blender that worked as expected) **Short description of error** Using X symmetry Grab or Scale on certain parts of a mesh - leaves an odd, seemingly random assortment of polygons unaffected on the opposite side of the mesh. Eg. massive polygon stretching occurs as random vertexes are left behind. **Exact steps for others to reproduce the error** [Turtle broken symmetry.blend](https://archive.blender.org/developer/F10347618/Turtle_broken_symmetry.blend) - Select turtle, - edit mode, - check that X Symmetry is enabled, - enable Xray view, - select one of the rear feet, - move it, you will see a bunch of vertices around the nails are left behind every time. The same occurs for rear feet., left-right or right-left, for scaling moving etc, and Select Mirror. It is acting as if the mesh is not symmetrical, in some parts, but it appears symmetrical to me and is symmetrical enough to cause z-fighting if i duplicate and mirror a foot. ![image.png](https://archive.blender.org/developer/F10347611/image.png)

Kit Matthews commented

2021-08-29 12:43:05 +02:00

Added subscriber: @kitdev

Kit Matthews changed title from ~~blender 2.93.1 X Symmetry and Select Mirror inconsistently affects vertices~~ to blender 2.93.1 , 2.93.3LTS X Symmetry and Select Mirror inconsistently affects vertices

2021-08-29 12:43:40 +02:00

Kit Matthews commented

2021-08-29 12:50:18 +02:00

I deleted, re-mirrored and re-joined the nails to try and work around the issue.
But the issue still occurs with new geometry

I deleted, re-mirrored and re-joined the nails to try and work around the issue. But the issue still occurs with new geometry

Pratik Borhade commented

2021-08-30 08:42:16 +02:00

Added subscriber: @PratikPB2123

Richard Antalik commented

2021-09-01 07:42:27 +02:00

Added subscriber: @iss

Richard Antalik commented

2021-09-01 07:42:27 +02:00

I can reproduce this issue, it seems to behave better when you disable Topology mirror mode, which shouldn't be the case. This case can be reproduced on rear legs, but there obe nail is malformed on one side.

Can you create simpler(as simple as possible) case where vertices should be mirrored but aren't? Or provide steps to create such mesh? Not sure if current file will be deemed as simple enough.

I can reproduce this issue, it seems to behave better when you disable Topology mirror mode, which shouldn't be the case. This case can be reproduced on rear legs, but there obe nail is malformed on one side. Can you create simpler(as simple as possible) case where vertices should be mirrored but aren't? Or provide steps to create such mesh? Not sure if current file will be deemed as simple enough.

Richard Antalik changed title from ~~blender 2.93.1 , 2.93.3LTS X Symmetry and Select Mirror inconsistently affects vertices~~ to Symmetry editing not working correctly

2021-09-01 07:45:19 +02:00

Richard Antalik commented

2021-09-01 07:45:19 +02:00

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