Boolean and Bevel werid behavior #72942

New Issue

Marcin Surma · 2020-01-06T23:43:05+01:00

Marcin Surma commented

2020-01-06 23:43:05 +01:00

System Information
Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce GTX 1050 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 432.00

Blender Version
Broken: version: 2.81a (sub 16), branch: master, commit date: 2019-12-04 11:32, hash: f1aa4d18d4
Worked: (optional)

Short description of error
The bevel factor varies somewhat unpredictably in some geometries.

Exact steps for others to reproduce the error
Open:
bug boolean.blend

Move the smaller object and note the bevel glitch.

2020-01-06 23-30-58.mp4

**System Information** Operating system: Windows-10-10.0.18362 64 Bits Graphics card: GeForce GTX 1050 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 432.00 **Blender Version** Broken: version: 2.81a (sub 16), branch: master, commit date: 2019-12-04 11:32, hash: `f1aa4d18d4` Worked: (optional) **Short description of error** The bevel factor varies somewhat unpredictably in some geometries. **Exact steps for others to reproduce the error** Open: [bug boolean.blend](https://archive.blender.org/developer/F8263470/bug_boolean.blend) * Move the smaller object and note the bevel glitch. [2020-01-06 23-30-58.mp4](https://archive.blender.org/developer/F8263460/2020-01-06_23-30-58.mp4)

Marcin Surma commented

2020-01-06 23:43:05 +01:00

Added subscriber: @WWS3D

Germano Cavalcante commented

2020-01-07 21:35:14 +01:00

Added subscribers: @howardt, @mano-wii

Germano Cavalcante commented

2020-01-07 21:35:15 +01:00

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

Germano Cavalcante commented

2020-01-07 21:35:15 +01:00

On blender 2.79, this did not happen.
At least not at this intensity.

@howardt, any idea what might be causing this?

On blender 2.79, this did not happen. At least not at this intensity. @howardt, any idea what might be causing this?

Marcin Surma commented

2020-01-09 13:06:33 +01:00

I my opinion ( I do not know about code ) : In wireframe mode we see that when boolean is on - there are created new lines on this top face in main object. At one time new lines connect to the cutting edge and at the other time to the vertex cutting corner depends on position of bool object. Bevel realy is just switch with boolean lines that are created by changing position of bool object. The same thing happens without bevel modifier.bug boolean 2.mp4

I think lines that are created in main object faces need to be consistant regardless of bool object position. On video we see clear that they connect to vertex or center of edge.

I my opinion ( I do not know about code ) : In wireframe mode we see that when boolean is on - there are created new lines on this top face in main object. At one time new lines connect to the cutting edge and at the other time to the vertex cutting corner depends on position of bool object. Bevel realy is just switch with boolean lines that are created by changing position of bool object. The same thing happens without bevel modifier.[bug boolean 2.mp4](https://archive.blender.org/developer/F8267418/bug_boolean_2.mp4) I think lines that are created in main object faces need to be consistant regardless of bool object position. On video we see clear that they connect to vertex or center of edge.

Howard Trickey commented

2020-01-09 15:52:05 +01:00

The lines are created in the top face are necessary because Blender doesn't allow holes to exist in faces without those holes being connected to the enclosing face by at least two edges. It is not easy to make those "support edges" get added at consistent vertices as you move things around, unfortunately, and the current code does't even try.

I agree that it is strange that Boolean sometimes creates new vertices in the middle of edges and connects there. I think it is because Boolean works on triangulated faces and then untriangulates them later, not always completely invisibly to the user. I am not inclined to work on making this better in the current Boolean code since I am working on completely new Boolean code that operates differently in many ways -- including not triangulating faces, and using a different algorithm to connect the support edges.

The bevel glitches in the original bug file are caused mainly be clamp_overlap -- because of where the support edges attach. If you turn that off, it will look less glitchy (except for the jumping of the support edge attach positions) but they some edge/faces will overlap I think.

This bug should probably closed as "known issue", which will hopefully be fixed or at least made better with the new boolean code.

The lines are created in the top face are necessary because Blender doesn't allow holes to exist in faces without those holes being connected to the enclosing face by at least two edges. It is not easy to make those "support edges" get added at consistent vertices as you move things around, unfortunately, and the current code does't even try. I agree that it is strange that Boolean sometimes creates new vertices in the middle of edges and connects there. I think it is because Boolean works on triangulated faces and then untriangulates them later, not always completely invisibly to the user. I am not inclined to work on making this better in the current Boolean code since I am working on completely new Boolean code that operates differently in many ways -- including not triangulating faces, and using a different algorithm to connect the support edges. The bevel glitches in the original bug file are caused mainly be clamp_overlap -- because of where the support edges attach. If you turn that off, it will look less glitchy (except for the jumping of the support edge attach positions) but they some edge/faces will overlap I think. This bug should probably closed as "known issue", which will hopefully be fixed or at least made better with the new boolean code.

Germano Cavalcante commented

2020-01-09 17:21:39 +01:00

Boolean also behaves differently in 2.79. So the problem may be really there.
Good to know that the new boolean code may fix this issue.

Here is the file in blender 2.79 to test:
bug boolean 279.blend

Boolean also behaves differently in 2.79. So the problem may be really there. Good to know that the new boolean code may fix this issue. Here is the file in blender 2.79 to test: [bug boolean 279.blend](https://archive.blender.org/developer/F8267603/bug_boolean_279.blend)

Marcin Surma commented

2020-01-10 16:04:38 +01:00

great to know that new boolean will be different. Im waiting for it for so long time and propably many people as well.
Can I ask will be finished with new relese 2.82?

If old boolean triangulate faces why vertex on center of edge? when Face is triangulated is cuted in half but from vert to vert.... not from center of line to vert. I do not uderstand this. If is angon is triangulated in different way... but in this case is simple one line through plane so this line will not be atatch to center of line. For me realy werid. :)

great to know that new boolean will be different. Im waiting for it for so long time and propably many people as well. Can I ask will be finished with new relese 2.82? If old boolean triangulate faces why vertex on center of edge? when Face is triangulated is cuted in half but from vert to vert.... not from center of line to vert. I do not uderstand this. If is angon is triangulated in different way... but in this case is simple one line through plane so this line will not be atatch to center of line. For me realy werid. :)

Howard Trickey commented

2020-01-10 19:09:46 +01:00

No, sorry, the new Boolean will not be in 2.82. Probably not even in 2.83. I thought I was close, but the pesky problems related to numerical issues have proven difficult to get right. I've spent the last 3 weeks redoing an underlying triangulation / intersection library that is core to the new code so that it will be extremely robust in the face of nearly-degenerate geometry. Sorry.

Marcin Surma commented

2020-01-11 16:46:38 +01:00

thats ok . Im not developer but I can help in testing and some... thinking out the box. cross fingers for your work. It will be great.:)

Howard Trickey self-assigned this 2020-11-07 21:55:33 +01:00

Howard Trickey commented

2020-11-07 21:55:33 +01:00

Changed status from 'Confirmed' to: 'Resolved'

Howard Trickey closed this issue

2020-11-07 21:55:33 +01:00

Howard Trickey commented

2020-11-07 21:55:33 +01:00

As far as I can tell, the new Exact mode fixes this bug.

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Boolean and Bevel werid behavior #72942