GPU Subivsion behaves different in Blender 3.2 #98717

New Issue

Rincewind · 2022-06-09T10:20:04+02:00

Rincewind commented

2022-06-09 10:20:04 +02:00

System Information
Operating system: Windows-10-10.0.19042-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 512.15

Blender Version
Broken: version: 3.2.0, branch: master, commit date: 2022-06-08 10:22, hash: e05e1e3691
Worked: 3.1.2

Short description of error
GPU Subivsion behaves different in Blender 3.2

Exact steps for others to reproduce the error

UPDATE

It's caused by a different behavior of the GPU subivsion between 3.1.2 and 3.2.
Not sure if this a bug or intended than GPU subivsion is affacting geo nodes different in 3.2 compared to 3.1.2

ORIGINAL DESCRIPTION:

Open the attached file in 3.1 and 3.2.
You will see that you are getting a different result:

scatter test.blend

3.1

3.2

Scatter is done with Scatter 5.1 in Blender 3.1.2

The author of Scatter said that this is a Blender issue, if the behavior of the geometry nodes are changed by the Blender devs.

**System Information** Operating system: Windows-10-10.0.19042-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 512.15 **Blender Version** Broken: version: 3.2.0, branch: master, commit date: 2022-06-08 10:22, hash: `e05e1e3691` Worked: 3.1.2 **Short description of error** GPU Subivsion behaves different in Blender 3.2 **Exact steps for others to reproduce the error** **UPDATE** It's caused by a different behavior of the GPU subivsion between 3.1.2 and 3.2. Not sure if this a bug or intended than GPU subivsion is affacting geo nodes different in 3.2 compared to 3.1.2 **ORIGINAL DESCRIPTION:** Open the attached file in 3.1 and 3.2. You will see that you are getting a different result: [scatter test.blend](https://archive.blender.org/developer/F13141273/scatter_test.blend) 3.1 ![scatter example 3.1.png](https://archive.blender.org/developer/F13141282/scatter_example_3.1.png) 3.2 ![scatter example 3.2.png](https://archive.blender.org/developer/F13141285/scatter_example_3.2.png) Scatter is done with Scatter 5.1 in Blender 3.1.2 The author of Scatter said that this is a Blender issue, if the behavior of the geometry nodes are changed by the Blender devs.

Rincewind commented

2022-06-09 10:20:04 +02:00

Added subscriber: @Rincewind3D-1

Dorian commented

2022-06-09 10:25:34 +02:00

Added subscriber: @BD3D

Dorian commented

2022-06-09 10:25:34 +02:00

Couldn't reproduce it, got the exact same render in 3.1.2 or 3.2{F13141292}

PS: this is using a geometry node "uber-nodetree" while disabling the related plugin, blender devs prefer a more isolated case with only the potential problematic nodes, otherwise they have too much nodes to dig into. While this looks indeed like a blender related issue maybe related to your hardware?,, please contact me first before doing any report related to creations, we'll make sure to present an isolated case to the developers

Couldn't reproduce it, got the exact same render in 3.1.2 or 3.2{[F13141292](https://archive.blender.org/developer/F13141292/3.1.png)} ![3.2.png](https://archive.blender.org/developer/F13141293/3.2.png) ![3.2.png](https://archive.blender.org/developer/F13141296/3.2.png) PS: this is using a geometry node "uber-nodetree" while disabling the related plugin, blender devs prefer a more isolated case with only the potential problematic nodes, otherwise they have too much nodes to dig into. **While this looks indeed like a blender related issue maybe related to your hardware?,**, please contact me first before doing any report related to creations, we'll make sure to present an isolated case to the developers

Rincewind commented

2022-06-09 10:45:07 +02:00

Update:

This is not a geometroy node or scatter issue.

If I disable in 3.1.2 gpu subivision it's looking in 3.1.2 exactly like in 3.2

In 3.2 enabling or disabling gpu subdivison does not have an affact of the result.

Not sure which Blender version is now working as intended.

Update: This is not a geometroy node or scatter issue. If I disable in 3.1.2 gpu subivision it's looking in 3.1.2 exactly like in 3.2 ![grafik.png](https://archive.blender.org/developer/F13141317/grafik.png) In 3.2 enabling or disabling gpu subdivison does not have an affact of the result. Not sure which Blender version is now working as intended.

Rincewind changed title from ~~Scatter result differs vom 3.1 to 3.2~~ to GPU Subivsion behaves different in Blender 3.2

2022-06-09 10:48:01 +02:00

Philipp Oeser commented

2022-06-09 12:32:31 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2022-06-09 12:32:31 +02:00

Would assume 3.2 is actually more correct here?
Will check when this changed

Would assume 3.2 is actually more correct here? Will check when this changed

Rincewind commented

2022-06-09 13:01:08 +02:00

Yes, I guess also that 3.2 may be more correct here, but that’s not helping for backwards compatibility.
I think it could be a bugfix which introduced a breaking change.

Yes, I guess also that 3.2 may be more correct here, but that’s not helping for backwards compatibility. I think it could be a bugfix which introduced a breaking change.

Rincewind commented

2022-06-09 15:53:23 +02:00

After some investigation I figured out that in Blender 3.1.2 the subdivision modifier with gpu creaes real geometry,
while in 3.2 only normals are created:

blender_w9wujimMKk.mp4

Subdivision modifier behavior matrix

Blender version	CPU	GPU
3.1.2	no changes to geometry or normals	adds geometry and normals
3.2	no changes to geometry or normals	adds normals

After some investigation I figured out that in Blender 3.1.2 the subdivision modifier with gpu creaes real geometry, while in 3.2 only normals are created: [blender_w9wujimMKk.mp4](https://archive.blender.org/developer/F13141717/blender_w9wujimMKk.mp4) Subdivision modifier behavior matrix | Blender version | CPU | GPU | -- | -- | -- | | 3.1.2 | no changes to geometry or normals | adds geometry and normals | 3.2 | no changes to geometry or normals | adds normals

Germano Cavalcante commented

2022-06-09 15:53:34 +02:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2022-06-09 15:53:34 +02:00

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

Germano Cavalcante closed this issue

2022-06-09 15:53:34 +02:00

Germano Cavalcante commented

2022-06-09 15:53:34 +02:00

From what I can see, the 3.1 that is broken here.
Geometry Nodes Modifier is ignoring the Subdivision modifier there.
3.1 is not LTS and since 3.2 has been released, I don't think 3.1 will have any more bug fixes.
Also, with the current GM nodes, unfortunately we can't do a trivial versioning here :\

I don't see many options, so I'm archiving the report as the bug is already resolved.

From what I can see, the 3.1 that is broken here. Geometry Nodes Modifier is ignoring the Subdivision modifier there. 3.1 is not LTS and since 3.2 has been released, I don't think 3.1 will have any more bug fixes. Also, with the current GM nodes, unfortunately we can't do a trivial versioning here :\ I don't see many options, so I'm archiving the report as the bug is already resolved.

Rincewind commented

2022-06-09 15:58:53 +02:00

In #98717#1371614, @mano-wii wrote:
From what I can see, the 3.1 that is broken here.
Geometry Nodes Modifier is ignoring the Subdivision modifier there.
3.1 is not LTS and since 3.2 has been released, I don't think 3.1 will have any more bug fixes.
Also, with the current GM nodes, unfortunately we can't do a trivial versioning here :\

I don't see many options, so I'm archiving the report as the bug is already resolved.

We just posted simultanly. Please check my latest post.

I'm not sure if Blender 3.2 behaves as it should.

If the GPU version should behave like CPU version, 3.2 should not genrate normals with subdivison.

I also think that the "bug" from 3.1 is a nice feature.
Maybe the subdivison modifier could get a checkbox to let geometry nodes affact the geometry from subdivision, but this time with the same behaviour as for GPU and CPU ;)

> In #98717#1371614, @mano-wii wrote: > From what I can see, the 3.1 that is broken here. > Geometry Nodes Modifier is ignoring the Subdivision modifier there. > 3.1 is not LTS and since 3.2 has been released, I don't think 3.1 will have any more bug fixes. > Also, with the current GM nodes, unfortunately we can't do a trivial versioning here :\ > > I don't see many options, so I'm archiving the report as the bug is already resolved. We just posted simultanly. Please check my latest post. I'm not sure if Blender 3.2 behaves as it should. If the GPU version should behave like CPU version, 3.2 should not genrate normals with subdivison. I also think that the "bug" from 3.1 is a nice feature. Maybe the subdivison modifier could get a checkbox to let geometry nodes affact the geometry from subdivision, but this time with the same behaviour as for GPU and CPU ;)

Germano Cavalcante commented

2022-06-09 16:47:11 +02:00

@Rincewind3D-1, thanks for the information.
As this is a different problem, it deserves a different report.
Done: #98735 (GPU Subdivision displays the normal overlay of the generated mesh vertices and loops)

@Rincewind3D-1, thanks for the information. As this is a different problem, it deserves a different report. Done: #98735 (GPU Subdivision displays the normal overlay of the generated mesh vertices and loops)

Philipp Oeser commented

2022-06-10 08:47:17 +02:00

The original issue (different behavior of 3.2/3.2) changed in a9b94e5f81 btw. so yeah, no bug here, 3.1 was just wrong (and there seems to be no point in keeping backward compatibility for buggy behavior)

The original issue (different behavior of 3.2/3.2) changed in a9b94e5f81 btw. so yeah, no bug here, 3.1 was just wrong (and there seems to be no point in keeping backward compatibility for buggy behavior)

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GPU Subivsion behaves different in Blender 3.2 #98717