Regression: Cycles doesn't use default color attributes with face corner domains. #103143

New Issue

Max Edge · 2022-12-11T20:39:47+01:00

Max Edge commented

2022-12-11 20:39:47 +01:00

System Information
Operating system: Linux-5.15.0-56-generic-x86_64-with-glibc2.35 64 Bits
Graphics card: NVIDIA GeForce RTX 4090/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 525.60.11

Blender Version
Broken: version: 3.5.0 Alpha, branch: master, commit date: 2022-12-10 12:43, hash: fe30856d83
Worked: 3.3.2

Apparently caused by 12becbf0df

Short description of error
The default color attribute for rendering is set by the camera icon, and it is the output of the Color Attribute node when no name is entered inside. In Cycles however, the output is always 0 if the color attribute belongs to the face corner domain.
This bug is not present in Eevee.

Exact steps for others to reproduce the error
Select an object and give it a material > Give it a color attribute on the face domain > Connect the color attribute to a shader or to the output without entering a name for the attribute > Render in cycles.

Example file
Example.blend

**System Information** Operating system: Linux-5.15.0-56-generic-x86_64-with-glibc2.35 64 Bits Graphics card: NVIDIA GeForce RTX 4090/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 525.60.11 **Blender Version** Broken: version: 3.5.0 Alpha, branch: master, commit date: 2022-12-10 12:43, hash: `fe30856d83` Worked: 3.3.2 Apparently caused by 12becbf0df **Short description of error** The default color attribute for rendering is set by the camera icon, and it is the output of the Color Attribute node when no name is entered inside. In Cycles however, the output is always 0 if the color attribute belongs to the face corner domain. This bug is not present in Eevee. ![Example.png](https://archive.blender.org/developer/F14052660/Example.png) **Exact steps for others to reproduce the error** Select an object and give it a material > Give it a color attribute on the face domain > Connect the color attribute to a shader or to the output without entering a name for the attribute > Render in cycles. **Example file** [Example.blend](https://archive.blender.org/developer/F14052663/Example.blend)

Max Edge commented

2022-12-11 20:39:47 +01:00

Added subscriber: @Max-49

Pratik Borhade commented

2022-12-12 04:46:51 +01:00

Added subscribers: @lichtwerk, @PratikPB2123

Pratik Borhade commented

2022-12-12 04:46:51 +01:00

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

Pratik Borhade commented

2022-12-12 04:46:51 +01:00

Hi, thanks for the report. I'm not really able to reproduce this in current master (05bf5c4e0ea8)
Could you check again in latest build: https://builder.blender.org/download/daily/
@lichtwerk , can you repro this on Linux?

**System Information**
Operating system: Windows-10-10.0.22000-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3050 Laptop GPU/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 512.78

Hi, thanks for the report. I'm not really able to reproduce this in current master (`05bf5c4e0ea8`) Could you check again in latest build: https://builder.blender.org/download/daily/ @lichtwerk , can you repro this on Linux? ``` **System Information** Operating system: Windows-10-10.0.22000-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 3050 Laptop GPU/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 512.78 ```

Max Edge commented

2022-12-12 06:18:21 +01:00

Hi, I still see the bug in 3.5, 3.4, but not 3.3.2. It is both my Windows and Linux OS, on both CPU and GPU rendering with cycles.

Pratik Borhade commented

2022-12-12 06:19:52 +01:00

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

Philipp Oeser commented

2022-12-12 09:38:52 +01:00

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

Philipp Oeser commented

2022-12-12 09:38:52 +01:00

I can confirm, too, will check.

Philipp Oeser commented

2022-12-12 10:44:14 +01:00

Added subscriber: @HooglyBoogly

Philipp Oeser commented

2022-12-12 10:44:14 +01:00

Apparently caused by 12becbf0df

CC @HooglyBoogly

Apparently caused by 12becbf0df CC @HooglyBoogly

Philipp Oeser changed title from ~~Cycles doesn't use default color attributes with face corner domains.~~ to Regression: Cycles doesn't use default color attributes with face corner domains.

2022-12-12 10:44:35 +01:00

Hans Goudey self-assigned this 2022-12-12 14:37:56 +01:00

Philipp Oeser commented

2022-12-12 18:35:14 +01:00

@HooglyBoogly : cycles seems to "see" internal attributes such as .select in attr_create_generic (but only for facecorners)

@HooglyBoogly : cycles seems to "see" internal attributes such as `.select` in `attr_create_generic` (but only for facecorners)

Hans Goudey commented

2022-12-13 21:41:12 +01:00

The RNA API should see "internal" attributes like .select/.hide, etc.. Those aren't meant to be hidden from the Python API.

The problem is that render_color_index doesn't count those attributes. The best solution I can think of is exposing the name of that attribute as a string.

The RNA API *should* see "internal" attributes like `.select`/`.hide`, etc.. Those aren't meant to be hidden from the Python API. The problem is that `render_color_index` _doesn't_ count those attributes. The best solution I can think of is exposing the name of that attribute as a string.

Hans Goudey commented

2022-12-13 22:12:38 +01:00

The problem is that the "render color index" skips attributes with non-color domains or types, but Cycles increments an index for every single attribute. So the problem was already there, it's just exposed by the fact that there's another attribute there.