Wrong order of Auto Smooth GN modifier #116395

New Issue

nameless · 2023-12-20T19:58:22+01:00

nameless commented

2023-12-20 19:58:22 +01:00

System Information
Operating system: Windows-10-10.0.19044-SP0 64 Bits
Graphics card: NVIDIA GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 537.34

Blender Version
Broken: version: 4.1.0 Alpha, branch: main, commit date: 2023-12-20 13:27, hash: 408bc52bedb7
Worked: 4.0 and older

Short description of error
In 4.1, Auto Smooth was moved to Geometry Nodes. Meshes from 4.0 and older blender versions, when loaded into 4.1, have added Auto Smooth GN. However, it causes incorrect shading. Moving Auto Smooth GN from bottom to top solves this issue entirely and shading looks exactly as in 4.0 and older versions.

This is how looks before moving Auto Smooth GN:

And this is after moving Auto Smooth GN from bottom of list to top:

Exact steps for others to reproduce the error

Open provided .blend file
In solid view, you can see strange shading (triangles/shadows)
Move Auto Smooth GN from bottom to top of list
Shading is correct now

In current state of 4.1, it would mean that for older projects to work properly in 4.1, I would have to adjust GN of dozens/hundreds meshes.

Would it be possible for 4.1 to move Auto Smooth GN automatically to top of list?

**System Information** Operating system: Windows-10-10.0.19044-SP0 64 Bits Graphics card: NVIDIA GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 537.34 **Blender Version** Broken: version: 4.1.0 Alpha, branch: main, commit date: 2023-12-20 13:27, hash: `408bc52bedb7` Worked: 4.0 and older **Short description of error** In 4.1, Auto Smooth was moved to Geometry Nodes. Meshes from 4.0 and older blender versions, when loaded into 4.1, have added Auto Smooth GN. However, it causes incorrect shading. Moving Auto Smooth GN from bottom to top solves this issue entirely and shading looks exactly as in 4.0 and older versions. This is how looks before moving Auto Smooth GN: ![1](/attachments/23c498c1-4f53-4699-880f-885657e2efa0) And this is after moving Auto Smooth GN from bottom of list to top: ![2](/attachments/d292bc23-42a9-43e8-b5da-c9dc077ee968) **Exact steps for others to reproduce the error** 1. Open provided .blend file 2. In solid view, you can see strange shading (triangles/shadows) 3. Move Auto Smooth GN from bottom to top of list 4. Shading is correct now In current state of 4.1, it would mean that for older projects to work properly in 4.1, I would have to adjust GN of dozens/hundreds meshes. Would it be possible for 4.1 to move Auto Smooth GN automatically to top of list?

AutoSmoothGN.blend

1.3 MiB

2.jpg

50 KiB

1.jpg

55 KiB

nameless added the

labels 2023-12-20 19:58:23 +01:00

Iliya Katushenock commented

2023-12-20 20:22:43 +01:00

@HooglyBoogly /

Pratik Borhade commented

2023-12-21 06:53:07 +01:00

Guess auto-smooth should be at bottom? Otherwise it'll tweak Normal before modifiers.

Pratik Borhade added

Module

Modeling

Status

Needs Info from Developers

and removed

Status

Needs Triage

labels 2023-12-21 06:53:20 +01:00

Hans Goudey commented

2023-12-21 16:47:48 +01:00

Hi, thanks for the report. I can confirm the change in your setup. But I'm not sure it's as simple as just moving the modifier to be first.

As far as I can tell, the previous behavior was that the split normals were calculated right before the weighted normal modifier. Moving the auto smooth modifier directly before the weighted normal modifier seems to work, except for a black artifact on the large trapezoid face. I'm not sure where that's coming from yet.

However, it also looks like just removing the new modifier works in your setup. "Auto smooth" was only necessary before because it was the only way to enable custom normals.

Hi, thanks for the report. I can confirm the change in your setup. But I'm not sure it's as simple as just moving the modifier to be first. As far as I can tell, the previous behavior was that the split normals were calculated right before the weighted normal modifier. Moving the auto smooth modifier directly before the weighted normal modifier seems to work, except for a black artifact on the large trapezoid face. I'm not sure where that's coming from yet. However, it also looks like just removing the new modifier works in your setup. "Auto smooth" was only necessary before because it was the only way to enable custom normals.

nameless commented

2023-12-21 17:19:56 +01:00

Hi, thanks for the report. I can confirm the change in your setup. But I'm not sure it's as simple as just moving the modifier to be first.

As far as I can tell, the previous behavior was that the split normals were calculated right before the weighted normal modifier. Moving the auto smooth modifier directly before the weighted normal modifier seems to work, except for a black artifact on the large trapezoid face. I'm not sure where that's coming from yet.

However, it also looks like just removing the new modifier works in your setup. "Auto smooth" was only necessary before because it was the only way to enable custom normals.

I've poked around black triangle and turns out in one corner there were 2 very close vertices instead of 1. So that's modeling error on my part. When those get merged into 1, the black triangle is gone. I've attached updated .blend file.

Thanks for reply, but I'm not sure what implications would be for future 4.1 release and opening my old projects. Or does it require further investigation? Sorry, I'm not super technically versed :)

> Hi, thanks for the report. I can confirm the change in your setup. But I'm not sure it's as simple as just moving the modifier to be first. > > As far as I can tell, the previous behavior was that the split normals were calculated right before the weighted normal modifier. Moving the auto smooth modifier directly before the weighted normal modifier seems to work, except for a black artifact on the large trapezoid face. I'm not sure where that's coming from yet. > > However, it also looks like just removing the new modifier works in your setup. "Auto smooth" was only necessary before because it was the only way to enable custom normals. > I've poked around black triangle and turns out in one corner there were 2 very close vertices instead of 1. So that's modeling error on my part. When those get merged into 1, the black triangle is gone. I've attached updated .blend file. Thanks for reply, but I'm not sure what implications would be for future 4.1 release and opening my old projects. Or does it require further investigation? Sorry, I'm not super technically versed :)

AutoSmoothGN_v2.blend

1.3 MiB

triangle.jpg

34 KiB

Pratik Borhade referenced this issue

2024-01-15 12:01:49 +01:00

Face Snapping causes HIPEW crash when backface culling is turned on in the snapping options #117094

nameless commented

2024-02-26 17:47:30 +01:00

Hi, thanks for the report. I can confirm the change in your setup. But I'm not sure it's as simple as just moving the modifier to be first.

As far as I can tell, the previous behavior was that the split normals were calculated right before the weighted normal modifier. Moving the auto smooth modifier directly before the weighted normal modifier seems to work, except for a black artifact on the large trapezoid face. I'm not sure where that's coming from yet.

However, it also looks like just removing the new modifier works in your setup. "Auto smooth" was only necessary before because it was the only way to enable custom normals.

Any update, @HooglyBoogly ? I've downloaded latest 4.1 build and the regression is still there - incorrect shading when loading older projects. 4.1 is getting closer to release day and I'm worried issue is dusting on shelf.

> Hi, thanks for the report. I can confirm the change in your setup. But I'm not sure it's as simple as just moving the modifier to be first. > > As far as I can tell, the previous behavior was that the split normals were calculated right before the weighted normal modifier. Moving the auto smooth modifier directly before the weighted normal modifier seems to work, except for a black artifact on the large trapezoid face. I'm not sure where that's coming from yet. > > However, it also looks like just removing the new modifier works in your setup. "Auto smooth" was only necessary before because it was the only way to enable custom normals. > Any update, @HooglyBoogly ? I've downloaded latest 4.1 build and the regression is still there - incorrect shading when loading older projects. 4.1 is getting closer to release day and I'm worried issue is dusting on shelf.

Hans Goudey commented

2024-02-28 05:16:18 +01:00

Thanks for the reminder. It's a bit tricky to generalize this while being confident about a proper conversion from all old files. But testing the file again, my current conclusion is that adding the modifier with versioning is unnecessary when the last modifier in the stack is a weighted normal modifier. This week I'll test that in some more cases. Hopefully it is that simple.

Hans Goudey added

and removed

Needs Info from Developers

Type

Report

labels 2024-03-08 21:58:39 +01:00

Hans Goudey referenced this issue from a commit

2024-03-08 22:09:56 +01:00

Fix #116395: Auto smooth versioning modifier added unnecessarily

Hans Goudey closed this issue

2024-03-08 22:37:16 +01:00

Blender Bot added

and removed

labels 2024-03-08 22:37:19 +01:00

nameless commented

2024-03-09 13:23:22 +01:00

Hi Hans, thanks for fix. I've loaded project and inspected, there's improvement, but there also still issue on assets that require auto smooth to be kept from blender 4.0. Basically 'Keep Sharp' option in Weighted Normal modifier doesn't work until there's auto smoothing. To get shading identical to what I have in 4.0 and earlier, I have to add Auto Smooth modifier above Weighted Normal modifier.

This is what asset looks in 4.0 (correct look)

In blender 4.1 (sharp/non-beveled edges aren't sharp). Toggling on/off the 'Keep Sharp' option in Weighted Normal modifier does very little compared to blender 4.0

When I add Auto Smooth modifier above Weighted Normal

The shading in 4.1 becomes correct - as in 4.0 - and toggling Keep Sharp option in Weighted Normal modifier also behaves exactly same as in 4.0.

Conclusion - adding conditional to not add Auto Smooth helped with shading, but not completely and the shading issue severity (mainly with keeping sharp edges sharp) depends on geometry of asset. I think in my case, if blender 4.1 detects both auto smoothing and Weighted Normal, it has to add Auto Smooth modifier with similar angle value above Weighted Normal? I'm not sure exactly what the issue is, but at current state, it's still not feasible for me to open older projects with auto smooth+bevel+weighted normal combo on hard surface assets - I would have to add Auto Smooth to all assets, above Weighted Normal modifiers to get their shading matched to blender 4.0.

I've attached simplified .blend file

EDIT: I realized that in 4.0, if auto smooth is disabled in mesh data properties, the Weighted Normal modifier shows a warning that auto smoothing has to be enabled for modifier to work properly, I guess this modifier still relies on auto smoothing in 4.1?

Hi Hans, thanks for fix. I've loaded project and inspected, there's improvement, but there also still issue on assets that require auto smooth to be kept from blender 4.0. Basically 'Keep Sharp' option in Weighted Normal modifier doesn't work until there's auto smoothing. To get shading identical to what I have in 4.0 and earlier, I have to add Auto Smooth modifier above Weighted Normal modifier. This is what asset looks in 4.0 (correct look) ![correct.png](/attachments/c6f84764-a7cc-4cc3-8141-6e2e831350b3) In blender 4.1 (sharp/non-beveled edges aren't sharp). Toggling on/off the 'Keep Sharp' option in Weighted Normal modifier does very little compared to blender 4.0 ![notsharp.png](/attachments/e8b06ad8-48a1-474a-b9b1-87562c09a006) When I add Auto Smooth modifier above Weighted Normal ![image](/attachments/6ae4cf8f-9e56-4406-9618-b42d69e73b58) The shading in 4.1 becomes correct - as in 4.0 - and toggling Keep Sharp option in Weighted Normal modifier also behaves exactly same as in 4.0. Conclusion - adding conditional to not add Auto Smooth helped with shading, but not completely and the shading issue severity (mainly with keeping sharp edges sharp) depends on geometry of asset. I think in my case, if blender 4.1 detects both auto smoothing and Weighted Normal, it has to add Auto Smooth modifier with similar angle value above Weighted Normal? I'm not sure exactly what the issue is, but at current state, it's still not feasible for me to open older projects with auto smooth+bevel+weighted normal combo on hard surface assets - I would have to add Auto Smooth to all assets, above Weighted Normal modifiers to get their shading matched to blender 4.0. I've attached simplified .blend file EDIT: I realized that in 4.0, if auto smooth is disabled in mesh data properties, the Weighted Normal modifier shows a warning that auto smoothing has to be enabled for modifier to work properly, I guess this modifier still relies on auto smoothing in 4.1?

correct.png

87 KiB

image.png

24 KiB

notsharp.png

180 KiB

AutoSmoothGN_missingAutoSmooth.blend

1.4 MiB

nameless reopened this issue

2024-03-09 13:23:26 +01:00

Blender Bot added

Status