BMesh boolean fails when edge is co-planar to face (under some circumstances) #54024

New Issue

32th System · 2018-02-07T21:17:07+01:00

32th System commented

2018-02-07 21:17:07 +01:00

System Information
Ubuntu 17.10, Intel HD Graphics

Blender Version
2.79

Short description of error
Boolean operations using BMesh may not work properly when I use cubes in combination with cylinders

Exact steps for others to reproduce the error
https://www.youtube.com/watch?v=LQyUePorgpA This video shows exactly what I did.

TEXT GUIDE:
Make a cylinder with the depth 6 and the radius 1
Make a second cylinder with the radius 0.8 and the depth 7
Make a Boolean operation (BMesh) to subtract the smaller cylinder from the bigger one
You now have a pipe.
Place a cube covering half of the pipe but bigger than the pipe
Do a Boolean operation (BMesh) on the pipe: difference with the cube.

The results should be that the pipe disappears or stays a whole pipe without getting anything cut of of it. The results seem to vary when you restart Blender and different rotations may also make a difference.
broken_bool.blend

**System Information** Ubuntu 17.10, Intel HD Graphics **Blender Version** 2.79 **Short description of error** Boolean operations using BMesh may not work properly when I use cubes in combination with cylinders **Exact steps for others to reproduce the error** https://www.youtube.com/watch?v=LQyUePorgpA This video shows exactly what I did. TEXT GUIDE: Make a cylinder with the depth 6 and the radius 1 Make a second cylinder with the radius 0.8 and the depth 7 Make a Boolean operation (BMesh) to subtract the smaller cylinder from the bigger one You now have a pipe. Place a cube covering half of the pipe but bigger than the pipe Do a Boolean operation (BMesh) on the pipe: difference with the cube. The results should be that the pipe disappears or stays a whole pipe without getting anything cut of of it. The results seem to vary when you restart Blender and different rotations may also make a difference. [broken_bool.blend](https://archive.blender.org/developer/F2181181/broken_bool.blend)

32th System commented

2018-02-07 21:17:07 +01:00

Added subscriber: @32th_System

blender-admin commented

2018-02-07 21:17:07 +01:00

#75867 was marked as duplicate of this issue

blender-admin commented

2018-02-07 21:17:07 +01:00

#72963 was marked as duplicate of this issue

blender-admin commented

2018-02-07 21:17:07 +01:00

#61845 was marked as duplicate of this issue

blender-admin commented

2018-02-07 21:17:07 +01:00

#71229 was marked as duplicate of this issue

blender-admin commented

2018-02-07 21:17:07 +01:00

#70371 was marked as duplicate of this issue

blender-admin commented

2018-02-07 21:17:07 +01:00

#60972 was marked as duplicate of this issue

Campbell Barton changed title from ~~Boolean operations with BMesh can cause interesting results~~ to BMesh boolean fails when edge is co-planar to face (under some circumstances)

2018-02-08 05:32:07 +01:00

Campbell Barton commented

2018-02-08 05:36:09 +01:00

Added subscriber: @ideasman42

Campbell Barton commented

2018-02-08 05:36:09 +01:00

I suspect the cause of this is a known issue comparing distances along the edge instead of global space.

This means an edge may not be considered exactly aligned to the face, and the edges on either side may also not be considered touching the face.

The solution is to move all distance comparisons into the same space (known TODO)

Notice this works if you :

Change overlap threshold to 0.0000001
Set the Cylinders Z scale to 0.4

I suspect the cause of this is a known issue comparing distances along the edge instead of global space. This means an edge may not be considered exactly aligned to the face, and the edges on either side may also not be considered touching the face. The solution is to move all distance comparisons into the same space (known TODO) Notice this works if you : - Change overlap threshold to 0.0000001 - Set the Cylinders Z scale to 0.4

32th System commented

2018-02-08 07:42:51 +01:00

Doing that did in fact make the Boolean operation work.

mathieu menuet commented

2018-03-03 17:09:37 +01:00

Added subscriber: @bliblubli

mathieu menuet commented

2018-03-03 17:09:37 +01:00

@ideasman42 As Carve boolean has been removed, would it be possible to finalize Bmesh version? Before user could use the other one as fallback, but now we have to use Bmesh. I'm happy to have only one variant if it's robust enough.

mathieu menuet commented

2018-03-27 11:09:57 +02:00

Addons relying on carve modifier are not working in master like this one https://blenderartists.org/forum/showthread.php?409837-Destructive-Extrude-BETA/page9 and the results of bmesh are not yet there in some cases (like overlapping/coplanar edges/faces).
I think it was a very good idea to keep only one version of the boolean modifier and bmesh is really fast, but it should offer as much as the old combination. Or is the plan to only remove functionality in this case?

Addons relying on carve modifier are not working in master like this one https://blenderartists.org/forum/showthread.php?409837-Destructive-Extrude-BETA/page9 and the results of bmesh are not yet there in some cases (like overlapping/coplanar edges/faces). I think it was a very good idea to keep only one version of the boolean modifier and bmesh is really fast, but it should offer as much as the old combination. Or is the plan to only remove functionality in this case?

Campbell Barton commented

2018-03-27 11:15:37 +02:00

The plan is to improve bmesh boolean to support overlap.

Michael New commented

2018-06-01 00:36:21 +02:00

Added subscriber: @CareAgain

Philipp Oeser commented

2019-01-29 10:07:29 +01:00

Added subscribers: @AdamPreisler, @lichtwerk

Philipp Oeser commented

2019-09-30 13:58:25 +02:00

Added subscriber: @boolean-4

Stefan commented

2019-10-23 12:32:54 +02:00

Added subscriber: @EvilReFlex

Stefan commented

2019-10-23 12:32:54 +02:00

This problem still occurs on the last 2.81 version (blender-2.81-ac18c3c28dee-windows64)

Open new project
add cylinder
move cylinder on x or y 1m
select one mesh
add boolen
use union with the other mesh

This problem is very annoying if you want to to some CAD like stuff.

This problem still occurs on the last 2.81 version (blender-2.81-ac18c3c28dee-windows64) - Open new project - add cylinder - move cylinder on x or y 1m - select one mesh - add boolen - use union with the other mesh This problem is very annoying if you want to to some CAD like stuff.

Philipp Oeser commented

2019-11-01 10:16:34 +01:00

Added subscribers: @belamat, @howardt, @Dspazio

Howard Trickey commented

2019-11-01 10:27:42 +01:00

This is very hard to fix with the current Boolean, and will be fixed with new Boolean code that I am writing. I'm hoping to have it done for 2.83. Or if things go very well in the next few weeks, 2.82.

Matias Bela commented

2019-11-01 12:29:08 +01:00

@howardt Great Howard, just wanted to mention in case you didn't know That in my case I could notice that the problem was when the objects were using the matrix coordinates example (0,0,0) or (0,1,1) I tested this with the snap to vertex tool and in the fixed coordinates didnt worked but the same did work with no fixed grid, (placing the object in any free place and then snaping to its vertex)

Thanks for your work!

@howardt Great Howard, just wanted to mention in case you didn't know That in my case I could notice that the problem was when the objects were using the matrix coordinates example (0,0,0) or (0,1,1) I tested this with the snap to vertex tool and in the fixed coordinates didnt worked but the same did work with no fixed grid, (placing the object in any free place and then snaping to its vertex) Thanks for your work!

Pablo Dobarro commented

2020-02-05 00:57:14 +01:00

Added subscriber: @PabloDobarro

Pablo Dobarro commented

2020-02-05 00:57:14 +01:00

As pointed by @howardt, this is a know issue of the current boolean code and will be fixed when the new boolean code is ready.

Campbell Barton commented

2020-02-12 06:00:40 +01:00

Added subscribers: @AxelMening-4, @Stan_Pancakes, @AdamJanz

Campbell Barton commented

2020-02-12 07:51:58 +01:00

Added subscribers: @FlintEastwood, @MattOstgard, @VukGardasevic, @timewave, @mont29, @dfelinto, @candreacchio, @StephenLeger, @maxivazquez, @RaffaeleDiBlasi, @michaelknubben, @rs2128, @Kent-Davis, @RUben, @tooomg

Hans Goudey commented

2020-04-18 20:08:39 +02:00

Added subscribers: @dlbogdan, @ankitm

Howard Trickey commented

2020-09-01 02:07:31 +02:00

Changed status from 'Confirmed' to: 'Resolved'

Howard Trickey closed this issue

2020-09-01 02:07:31 +02:00

Howard Trickey self-assigned this 2020-09-01 02:07:31 +02:00

Howard Trickey commented

2020-09-01 02:07:31 +02:00

This is fixed if one uses the new Exact mode. commit 9e09b5c418

This is fixed if one uses the new Exact mode. commit 9e09b5c418

Kent Davis commented

2020-09-02 09:43:41 +02:00

Blender 2.91 Alpha for MacOS 11
There is not resolve. I inspect again Boolean error still.

Original .blend
Blender 2_91_alpha Sept 2 2020.blend

After Bool is error
Blender Error boolean 2_91_alpha Sept 2 2020.blend

Blender 2.91 Alpha for MacOS 11 There is not resolve. I inspect again Boolean error still. ![Screen Shot 2020-09-02 at 12.34.12 AM.png](https://archive.blender.org/developer/F8831908/Screen_Shot_2020-09-02_at_12.34.12_AM.png) Original .blend [Blender 2_91_alpha Sept 2 2020.blend](https://archive.blender.org/developer/F8831914/Blender_2_91_alpha_Sept_2_2020.blend) After Bool is error [Blender Error boolean 2_91_alpha Sept 2 2020.blend](https://archive.blender.org/developer/F8831919/Blender_Error_boolean_2_91_alpha_Sept_2_2020.blend)

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BMesh boolean fails when edge is co-planar to face (under some circumstances) #54024