Pinching effect when using bevel and bevel modifier #95916

New Issue

tempdevnova · 2022-02-20T19:21:16+01:00

tempdevnova commented

2022-02-20 19:21:16 +01:00

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 431.07

Blender Version
Broken: version: 3.0.0, branch: master, commit date: 2021-12-02 18:35, hash: f1cca30557
Worked: (newest version of Blender that worked as expected)

Short description of error
When using bevel in editing mode or bevel modifier sometimes a pinching effect happens at the beveled corners.

Exact steps for others to reproduce the error
When using bevel in editing mode or bevel modifier sometimes a pinching effect happens at the beveled corners.
This is particularly visible when using many segments.

Test file:
Bevel_test_file.blend

At first I thought, that this was some kind of limitation of the bevel operation/modifier, however after observing the top part of the test file mesh i'm very sure that this is a bug, because the left part of the topmost face of the test file mesh has a correctly beveled corner, whileas on the other side there is a clearly visible pinching effect despite the local topology of both sides of the topmost face being indentical.

Thank you and have a nice day!

**System Information** Operating system: Windows-10-10.0.19041-SP0 64 Bits Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 431.07 **Blender Version** Broken: version: 3.0.0, branch: master, commit date: 2021-12-02 18:35, hash: `f1cca30557` Worked: (newest version of Blender that worked as expected) **Short description of error** When using bevel in editing mode or bevel modifier sometimes a pinching effect happens at the beveled corners. **Exact steps for others to reproduce the error** When using bevel in editing mode or bevel modifier sometimes a pinching effect happens at the beveled corners. This is particularly visible when using many segments. Test file: [Bevel_test_file.blend](https://archive.blender.org/developer/F12879032/Bevel_test_file.blend) At first I thought, that this was some kind of limitation of the bevel operation/modifier, however after observing the top part of the test file mesh i'm very sure that this is a bug, because the left part of the topmost face of the test file mesh has a correctly beveled corner, whileas on the other side there is a clearly visible pinching effect despite the local topology of both sides of the topmost face being indentical. Thank you and have a nice day!

tempdevnova commented

2022-02-20 19:21:16 +01:00

Added subscriber: @tempdevnova

Richard Antalik commented

2022-02-20 20:13:06 +01:00

Added subscriber: @iss

Richard Antalik commented

2022-02-20 20:13:06 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Richard Antalik commented

2022-02-20 20:13:06 +01:00

Can reproduce in version 3.1 but not 3.2. Please check if this issue exists in latest alpha build from https://builder.blender.org/download/daily/

tempdevnova commented

2022-02-21 16:22:21 +01:00

I just tried it in th latest alpha build(3.2). Here are the results:

Master 3.0:

Alpha 3.2:

As you can clearly see on the top face it is clearly still broken... just differently.
It does seem to look a little better on sharp angles, but it definitely got worse in the case of obtuse angles, as you now have this kind of bump in the corners.
But apart from that it is wrong in both cases anyways, as the top face still should have identical bevel profiles.

I just tried it in th latest alpha build(3.2). Here are the results: Master 3.0: ![untitled.png](https://archive.blender.org/developer/F12880847/untitled.png) Alpha 3.2: ![untitled1.png](https://archive.blender.org/developer/F12880851/untitled1.png) As you can clearly see on the top face it is clearly still broken... just differently. It does seem to look a little better on sharp angles, but it definitely got worse in the case of obtuse angles, as you now have this kind of bump in the corners. But apart from that it is wrong in both cases anyways, as the top face still should have identical bevel profiles.

Richard Antalik commented

2022-03-01 01:43:38 +01:00

Changed status from 'Needs User Info' to: 'Needs Triage'

Richard Antalik commented

2022-03-01 01:43:38 +01:00

Added subscribers: @mano-wii, @howardt

Richard Antalik commented

2022-03-01 01:43:38 +01:00

Yes, you are correct, it's still different than other edges. Setting Limit Method to None or Miter Outer to arc seems to affect this particular corner, but not quite sure why or whether this is expected. @mano-wii, @howardt can you check?

tempdevnova commented

2022-03-02 16:23:11 +01:00

Pretty sure it's not expected, otherwise they wouldn't have changed it in the first place.
The Problem is just that the fix kind of doesn't work.

Pretty sure it's not expected, otherwise they wouldn't have changed it in the first place. The Problem is just that the fix kind of doesn't work.

Omar Emara commented

2022-03-07 11:36:12 +01:00

Added subscriber: @OmarEmaraDev

Omar Emara commented

2022-03-07 11:36:12 +01:00

Changed status from 'Needs Triage' to: 'Needs Developer To Reproduce'

Omar Emara commented

2022-03-07 11:36:12 +01:00

Simple steps to reproduce from scratch and investigation.

Add a cube.
Add a horizontal loop cut.
Add a bevel modifier with 20 segments.
Select one of the base edges.
Move the edge slightly in its perpendicular axis.
Two of the vertices in the cube pinch.
Change width type to absolute. Pinching is gone.
Revert width type to offset.
Disable loop slide. Pinching is gone.
Revert loop slide to enabled.
Change limit method to none. Pitching is gone.
Check the pinching at the loop cut.

20220307-123137.mp4

Simple steps to reproduce from scratch and investigation. - Add a cube. - Add a horizontal loop cut. - Add a bevel modifier with 20 segments. - Select one of the base edges. - Move the edge slightly in its perpendicular axis. - Two of the vertices in the cube pinch. - Change width type to absolute. Pinching is gone. - Revert width type to offset. - Disable loop slide. Pinching is gone. - Revert loop slide to enabled. - Change limit method to none. Pitching is gone. - Check the pinching at the loop cut. [20220307-123137.mp4](https://archive.blender.org/developer/F12900396/20220307-123137.mp4)

tempdevnova commented

2022-03-09 18:57:14 +01:00

I think that this task needs higher attention, because the bevel modifier is fundamental for most hard surface workflows and because the pinching becomes clearly visible after 7-8 segments (when using shade smooth or weighted normals) it means that it basically is useless for high poly models where round edges are a must.
What makes this worse is that this bug not only affects the bevel modifier but is also present with edit mode bevel operation! This means that apart from not being able to use the bevel modifier as a nice edge rounder it also can't be used in the general design process.
Here is a part of one of my actual hard surface assets:
Bevel_pinching.blend
All bevels were created in edit mode. As you can see, despite using only 4 segments for the bevel the "pinching" is clearly visible leading to shading issues later down the line, which no amount of weighted normals or smooth shading can solve.
I think that the problem with the bevel modifier has the same cause as that of the bevel operation in edit mode and as can be seen in my test file not only affects the corners but also the edges, so wouldn't really call it just pinching.
And to really drive my point home here is the problem clearly visible:

Bevel_pinching2.blend
Just look at the horrendous edges!

This is a problem that I already noticed in previous Blender versions, but thought that it was somehow a problem caused by user incompetence, but after all this time I'm sure that this is a bug that seriously needs to be addressed as quickly as possible.
And quite honestly it also baffles me how nobody has already noticed this issue prior to this but the world is full of wonders I guess...

Anyways, thank you and have a great day!

I think that this task needs higher attention, because the bevel modifier is fundamental for most hard surface workflows and because the pinching becomes clearly visible after 7-8 segments (when using shade smooth or weighted normals) it means that it basically is useless for high poly models where round edges are a must. What makes this worse is that this bug not only affects the bevel modifier but is also present with edit mode bevel operation! This means that apart from not being able to use the bevel modifier as a nice edge rounder it also can't be used in the general design process. Here is a part of one of my actual hard surface assets: [Bevel_pinching.blend](https://archive.blender.org/developer/F12914447/Bevel_pinching.blend) All bevels were created in edit mode. As you can see, despite using only 4 segments for the bevel the "pinching" is clearly visible leading to shading issues later down the line, which no amount of weighted normals or smooth shading can solve. I think that the problem with the bevel modifier has the same cause as that of the bevel operation in edit mode and as can be seen in my test file not only affects the corners but also the edges, so wouldn't really call it just pinching. And to really drive my point home here is the problem clearly visible: ![Bevel_problems.png](https://archive.blender.org/developer/F12914472/Bevel_problems.png) [Bevel_pinching2.blend](https://archive.blender.org/developer/F12914478/Bevel_pinching2.blend) Just look at the horrendous edges! This is a problem that I already noticed in previous Blender versions, but thought that it was somehow a problem caused by user incompetence, but after all this time I'm sure that this is a bug that seriously needs to be addressed as quickly as possible. And quite honestly it also baffles me how nobody has already noticed this issue prior to this but the world is full of wonders I guess... Anyways, thank you and have a great day!

Henrik D. commented

2022-05-15 14:42:02 +02:00

Added subscriber: @HDMaster84

Henrik D. commented

2022-05-15 14:42:02 +02:00

@tempdevnova In your test file Bevel_pinching2.blend it is clearly a user problem, as the faces are non planar. Bevel mostly works with non planar surfaces, but normals behave different and happen to cause problems.

I can however confirm the weird behavior in the actual bug report.
The problem is likely that the cube corner special case gets disabled by mistake by the algorithm.

@tempdevnova In your test file Bevel_pinching2.blend it is clearly a user problem, as the faces are non planar. Bevel mostly works with non planar surfaces, but normals behave different and happen to cause problems. I can however confirm the weird behavior in the actual bug report. The problem is likely that the cube corner special case gets disabled by mistake by the algorithm.

tempdevnova commented

2022-05-15 15:14:20 +02:00

@HDMaster84 is that a known limitation?

Philipp Oeser removed the

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Pinching effect when using bevel and bevel modifier #95916