Geometry nodes mesh boolean fails on certain values #114480

New Issue

Robert S · 2023-11-04T11:26:21+01:00

Robert S commented

2023-11-04 11:26:21 +01:00

System Information
Operating system: Windows-10-10.0.19045-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3090/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 537.34

Blender Version
Broken: version: 3.6.5, branch: blender-v3.6-release, commit date: 2023-10-16 14:30, hash: cf1e1ed46b7e
Worked: (newest version of Blender that worked as expected)

Short description of error
Two shapes originally look like this:

But the mesh boolean result is this:

The shapes are generated with the nodes available, and are nothing special. I don't see why the mesh boolean node has to fail on these rather simple shapes. And if you want to smoothly animate something like the "arc" value then you will get flickering (for example with arc values 90, 193, 295).

Hole tolerant option is also not an acceptable workaround because you get very jagged edges along the bottom, and if you have to do a second round of booleans to get rid of those, there's a risk that the same issues re-appear anyway.

Exact steps for others to reproduce the error

Open BooleanTest_simplified.blend
or
Open the attached example
Enable/disable the DEBUG boolean on the geo node modifier to see the original shapes
Change rings/arc input values to see when the boolean fails (especially arc at 90, 193, 295)

**System Information** Operating system: Windows-10-10.0.19045-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 3090/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 537.34 **Blender Version** Broken: version: 3.6.5, branch: blender-v3.6-release, commit date: 2023-10-16 14:30, hash: `cf1e1ed46b7e` Worked: (newest version of Blender that worked as expected) **Short description of error** Two shapes originally look like this: ![image](/attachments/b78b670e-eb85-4a14-adab-ff18f562d8b0) But the mesh boolean result is this: ![image](/attachments/517d6a9c-b308-4868-b416-21cd2f781171) The shapes are generated with the nodes available, and are nothing special. I don't see why the mesh boolean node has to fail on these rather simple shapes. And if you want to smoothly animate something like the "arc" value then you will get flickering (for example with arc values 90, 193, 295). Hole tolerant option is also not an acceptable workaround because you get very jagged edges along the bottom, and if you have to do a second round of booleans to get rid of those, there's a risk that the same issues re-appear anyway. **Exact steps for others to reproduce the error** - Open [BooleanTest_simplified.blend](/attachments/895e5488-327e-43d0-a8ab-80e135f32c91) or - Open the attached example - Enable/disable the DEBUG boolean on the geo node modifier to see the original shapes - Change rings/arc input values to see when the boolean fails (especially arc at 90, 193, 295)

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BooleanTest.zip

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Robert S added the

labels 2023-11-04 11:26:22 +01:00

Germano Cavalcante commented

2023-11-06 15:33:54 +01:00

Thanks for the report. Could you simplify the .blend file to narrow down the problem?

It is very complex. The only Boolean node that I identified to be intersecting the mesh itself. I'm not sure if it's intentional.

Normally .blend files can be simplified by removing most objects, joining then, and disabling settings, until the problem reveals itself more clearly.

Thanks for the report. Could you simplify the .blend file to narrow down the problem? It is very complex. The only Boolean node that I identified to be intersecting the mesh itself. I'm not sure if it's intentional. Normally .blend files can be simplified by removing most objects, joining then, and disabling settings, until the problem reveals itself more clearly.

Germano Cavalcante added

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Status

Needs Triage

labels 2023-11-06 15:34:05 +01:00

Robert S commented

2023-11-07 19:05:00 +01:00

I'm puzzled by how the file compresses very small, but expands quite large, but it is a minimal example...

Can an intersecting pie shape with a sphere be made simpler? If so, I'd like to know.

Regardless, I've removed the "debug" nodes and the corner case nodes now and updated the zip-file.

I'm also attaching a video which shows the issues.

I'm puzzled by how the file compresses very small, but expands quite large, but it _is_ a minimal example... Can an intersecting pie shape with a sphere be made simpler? If so, I'd like to know. Regardless, I've removed the "debug" nodes and the corner case nodes now and updated the zip-file. I'm also attaching a video which shows the issues.

boolean-arc.mp4

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Germano Cavalcante commented

2023-11-07 21:30:15 +01:00

Can an intersecting pie shape with a sphere be made simpler? If so, I'd like to know.

Attached an expected simplified .blend (no nodes, no generating objects, just the boolean).

Even so, the issue has not yet been truly identified as it could be a duplicate of any of these other issues:
#103315: Boolean modifier produces unexpected result
#102124: Boolean modifier assigns wrong material
#98183: Boolean modifier artifacts
#93568: Boolean modifier: Self Intersection fails when mesh object is same for both operand types
#88012: boolean node in geometry nodes seems to work wrong
#87866: Boolean modifier - Intersect option - not working / artifacts while doing 3D Sectioning

Could it be that it is coplanar edges causing the problem? Could it be that the mesh is not a manifold?
Anyway, I'm confirming it for the developers to take a look.

@howardt, maybe you'd be interested in this one?

> Can an intersecting pie shape with a sphere be made simpler? If so, I'd like to know. Attached an expected simplified .blend (no nodes, no generating objects, just the boolean). Even so, the issue has not yet been truly identified as it could be a duplicate of any of these other issues: #103315: Boolean modifier produces unexpected result #102124: Boolean modifier assigns wrong material #98183: Boolean modifier artifacts #93568: Boolean modifier: Self Intersection fails when mesh object is same for both operand types #88012: boolean node in geometry nodes seems to work wrong #87866: Boolean modifier - Intersect option - not working / artifacts while doing 3D Sectioning Could it be that it is coplanar edges causing the problem? Could it be that the mesh is not a manifold? Anyway, I'm confirming it for the developers to take a look. @howardt, maybe you'd be interested in this one?

BooleanTest_simplified.blend

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Germano Cavalcante added

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Needs Information from User

labels 2023-11-07 21:32:56 +01:00

Oken-Nendan commented

2024-02-23 15:59:22 +01:00

I have a similar problem here. I think it is the solver, the problem could be solved by adding the one or two other boolean solvers that the original Blender modifiers had.
I remember that the brl-cad solver was incorporated in the Blender3d source code at some time in story. Blender foundation should consider other options such as incorporating other solvers such as the one used by openscad.

The images show a bug in the union boolean of geonodes. Union between a circle of cubes and a cylinder used for creating a procedural gear. This bug is not hard to reproduce, just play a bit with the mesh boolean modifier (use nodes to change angle and position of objects before the mesh boolean operation) and it will appear. Version: Blender3d 4.0

I have a similar problem here. I think it is the solver, the problem could be solved by adding the one or two other boolean solvers that the original Blender modifiers had. I remember that the brl-cad solver was incorporated in the Blender3d source code at some time in story. Blender foundation should consider other options such as incorporating other solvers such as the one used by openscad. The images show a bug in the union boolean of geonodes. Union between a circle of cubes and a cylinder used for creating a procedural gear. This bug is not hard to reproduce, just play a bit with the mesh boolean modifier (use nodes to change angle and position of objects before the mesh boolean operation) and it will appear. Version: Blender3d 4.0 ![image](/attachments/404a3825-40b0-4c8c-b8ad-f44e1dda4fe7) ![image](/attachments/a25d8a9a-7499-4f44-a412-bfbca28d8f18)

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Oken-Nendan commented

2024-02-24 01:07:16 +01:00

@mano-wii @RobertS enabling the Face Orientation option can help debugging it. Normals are NOT flipped when you extrude a grid plane(because the extruded plane stops existing, so it needs to be duplicated and flipped as it would be in edit mode). Also Blender allows to create cylinders with negative radius and negative depth, which I'm sure will have flipped normals. This may lead to a lot of problems, and we need urgently a 'recalculate normals outside' node... Don't forget the mesh boolean is still a criminal, even with normals corrected.

@mano-wii @RobertS enabling the **Face Orientation** option can help debugging it. Normals are NOT flipped when you extrude a grid plane(because the extruded plane stops existing, so it needs to be duplicated and **flipped** as it would be in edit mode). Also Blender allows to create cylinders with negative radius and negative depth, which I'm sure will have flipped normals. This may lead to a lot of problems, and we need urgently a 'recalculate normals outside' node... Don't forget the mesh boolean is still a criminal, even with normals corrected. ![image](/attachments/542a7248-c0a7-4e73-89dd-a77e96c76587) ![image](/attachments/62ccee48-ed78-4a0d-b273-c296a80bd8e0) ![image](/attachments/9e338fc1-e00a-44f8-9ade-d6036ef951e8)

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Oken-Nendan commented

2024-02-24 01:51:25 +01:00

I've been playing a bit with it and it seems the problem is caused by normals.
this problem can be solved by just rotating meshes(or Flip Faces node) but can't be solved for complex meshes. Some users over the internet have tried (unsuccessfully) creating an artificial recalculate normals group node...

https://blender.stackexchange.com/questions/276473/recalculate-normals-of-an-object-using-geometry-nodes

![image](/attachments/0aabbdd3-bd65-4dc1-884d-131d2601db7f) I've been playing a bit with it and it seems the problem is caused by normals. this problem can be solved by just rotating meshes(or Flip Faces node) but can't be solved for complex meshes. Some users over the internet have tried (unsuccessfully) creating an artificial recalculate normals group node... [https://blender.stackexchange.com/questions/276473/recalculate-normals-of-an-object-using-geometry-nodes](https://blender.stackexchange.com/questions/276473/recalculate-normals-of-an-object-using-geometry-nodes)

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Oken-Nendan commented

2024-02-24 02:05:07 +01:00

XD

I can't believe it...
I wonder if the mesh boolean modifier will behave correctly with other objects... what kind of problems can happen...
this view option should be enabled automatically when we create a new geometry node :P

![image](/attachments/207ef017-185c-4cd3-af94-00873ae4b9d7) ![image](/attachments/c9df91bb-c2ac-47f3-9fdf-3aec7c97e0b9) XD I can't believe it... I wonder if the mesh boolean modifier will behave correctly with other objects... what kind of problems can happen... this view option should be enabled automatically when we create a new geometry node :P

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Geometry nodes mesh boolean fails on certain values #114480