inconsistency between cycles and eevee regard undefined attribute value #100120

New Issue

bar · 2022-08-01T14:22:25+02:00

bar commented

2022-08-01 14:22:25 +02:00

System Information
Operating system: Windows-10-10.0.19044-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3080 Laptop GPU/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 516.59

Blender Version
Broken: version: 3.1.2, branch: master, commit date: 2022-03-31 17:40, hash: cc66d1020c
Worked: (newest version of Blender that worked as expected)

Short description of error
cycles shows black when trying to use undefined attribute.
eevee shows error pink color.

notice eyebrows and hair.

**System Information** Operating system: Windows-10-10.0.19044-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 3080 Laptop GPU/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 516.59 **Blender Version** Broken: version: 3.1.2, branch: master, commit date: 2022-03-31 17:40, hash: `cc66d1020c` Worked: (newest version of Blender that worked as expected) **Short description of error** cycles shows black when trying to use undefined attribute. eevee shows error pink color. notice eyebrows and hair. ![cycles.png](https://archive.blender.org/developer/F13329310/cycles.png) ![eevee.png](https://archive.blender.org/developer/F13329321/eevee.png)

bar commented

2022-08-01 14:22:25 +02:00

Added subscriber: @barakooda

Omar Emara commented

2022-08-01 15:09:47 +02:00

Added subscriber: @OmarEmaraDev

Omar Emara commented

2022-08-01 15:09:47 +02:00

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

Omar Emara commented

2022-08-01 15:09:47 +02:00

I can't reproduce that myself. Both return black in case an attribute doesn't exist.
Are you sure that it is not a missing texture or something? Can you share that file or a simplified version of it?

I can't reproduce that myself. Both return black in case an attribute doesn't exist. Are you sure that it is not a missing texture or something? Can you share that file or a simplified version of it?

bar commented

2022-08-01 16:43:20 +02:00

Sorry, you very right.
for_new_segmentation_small_b.blend

Sorry, you very right. [for_new_segmentation_small_b.blend](https://archive.blender.org/developer/F13329520/for_new_segmentation_small_b.blend)

Omar Emara commented

2022-08-01 16:59:28 +02:00

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

Omar Emara closed this issue

2022-08-01 16:59:28 +02:00

Omar Emara commented

2022-08-01 16:59:28 +02:00

I assume you mean it was a missing texture indeed. In this case, we can archive that.

bar commented

2022-08-01 17:12:48 +02:00

nope -
the "a" pass is black
in eevee
is blue.

simply
inconsistency between cycles and eevee regard undefined attribute name\value

nope - the "a" pass is black in eevee is blue. simply inconsistency between cycles and eevee regard undefined attribute name\value ![01_eevee.png](https://archive.blender.org/developer/F13329586/01_eevee.png) ![01_cyccles.png](https://archive.blender.org/developer/F13329591/01_cyccles.png)

Omar Emara commented

2022-08-01 17:13:56 +02:00

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

Omar Emara reopened this issue

2022-08-01 17:13:56 +02:00

bar changed title from ~~inconsistency between cycles and eevee regard undefined value~~ to inconsistency between cycles and eevee regard undefined attribute value

2022-08-01 17:16:11 +02:00

Germano Cavalcante commented

2022-08-01 23:04:29 +02:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2022-08-01 23:04:29 +02:00

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

Germano Cavalcante commented

2022-08-01 23:04:29 +02:00

I can reproduce the issue, but the file is too complex and therefore not suitable for a bug report.
We require the bug reporter to narrow down the problem.
Normally .blend files can be simplified by removing most objects and disabling settings, until the problem reveals itself more clearly.

From what I can see, the problematic material fetches the body_parts_segmentation attribute on the mesh.
But the mesh with the material doesn't have the body_parts_segmentation attribute. It is found in another object.
So, a guess, the result seen seems to be an undefined behavior.

I can reproduce the issue, but the file is too complex and therefore not suitable for a bug report. We require the bug reporter to narrow down the problem. Normally .blend files can be simplified by removing most objects and disabling settings, until the problem reveals itself more clearly. From what I can see, the problematic material fetches the `body_parts_segmentation` attribute on the mesh. But the mesh with the material doesn't have the `body_parts_segmentation` attribute. It is found in another object. So, a guess, the result seen seems to be an undefined behavior.

bar commented

2022-08-02 10:58:08 +02:00

added simplified file with two objects - both contain same issue.
anything else i can help with ?
thank you and keep up the great work.for_new_segmentation_small_b.blend

added simplified file with two objects - both contain same issue. anything else i can help with ? thank you and keep up the great work.[for_new_segmentation_small_b.blend](https://archive.blender.org/developer/F13330968/for_new_segmentation_small_b.blend)

Germano Cavalcante commented

2022-08-03 15:48:09 +02:00

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

Germano Cavalcante closed this issue

2022-08-03 15:48:09 +02:00

Germano Cavalcante commented

2022-08-03 15:48:09 +02:00

A simplified file would look something like this:
hair_material_with_non-existing_attribute__bug.blend

The problem in fact is what was mentioned before.
The body_parts_segmentation attribute does not exist in the mesh.
The fact that a blue color appears is an undefined behavior.
Cycles displays black in this case, Eevee for some reason displays blue but the color is not defined.

Surely Eevee and Cycles should behave the same in these cases. However the report needs to be edited or a new one created to explain the real bug.

But this doesn't have much priority as it is an undefined behavior and the old hair system will soon be replaced.

A simplified file would look something like this: [hair_material_with_non-existing_attribute__bug.blend](https://archive.blender.org/developer/F13333947/hair_material_with_non-existing_attribute__bug.blend) The problem in fact is what was mentioned before. The `body_parts_segmentation` attribute does **not exist** in the mesh. The fact that a blue color appears is an undefined behavior. Cycles displays black in this case, Eevee for some reason displays blue but the color is not defined. Surely Eevee and Cycles should behave the same in these cases. However the report needs to be edited or a new one created to explain the real bug. But this doesn't have much priority as it is an undefined behavior and the old hair system will soon be replaced.

Germano Cavalcante commented

2022-08-03 16:03:41 +02:00

Closed as duplicate of #100174

Germano Cavalcante closed this issue

2022-08-03 16:03:41 +02:00

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inconsistency between cycles and eevee regard undefined attribute value #100120