Blender 4.1+ defaults to transparent shadows off on default material #120762

New Issue

Lalit Kumar · 2024-04-18T04:29:52+02:00

Lalit Kumar commented

2024-04-18 04:29:52 +02:00

System Information
Operating system: Linux-6.7.12-1-MANJARO-x86_64-with-glibc2.39 64 Bits, WAYLAND UI
Graphics card: NVIDIA GeForce GTX 1660 Ti/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 550.67

Blender Version
Broken: version: 4.1.1, branch: blender-v4.1-release, commit date: 2024-04-15 15:11, hash: e1743a0317bc
Worked: 4.0.2

Short description of error
The default material in the default scene has the transparent shadows option turned off in Blender 4.1+.

Steps to reproduce

Select from the top of Blender File -> Defaults -> Load Factory Settings
In the new default scene change the render engine to Cycles
Select the cude from the default scene and go to the material properties tab.
On the default material, you will find that transparent shadows is off. (The transparent shadows option can be found here in Material Properties -> Settings -> Surface -> Transparent Shadows)
Compare this to Blender 4.0

Report
"Light Path Node > Is Shadow Ray" is not working in Cycles in Blender 4.1+. The light is not passing through the glass material i created with "Light Path > Is Shadow Ray" in Cycles in 4.1+, whereas the same works in Blender 4.0, 4.0.1, and 4.0.2.

**System Information** Operating system: Linux-6.7.12-1-MANJARO-x86_64-with-glibc2.39 64 Bits, WAYLAND UI Graphics card: NVIDIA GeForce GTX 1660 Ti/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 550.67 **Blender Version** Broken: version: 4.1.1, branch: blender-v4.1-release, commit date: 2024-04-15 15:11, hash: `e1743a0317bc` Worked: 4.0.2 **Short description of error** The default material in the default scene has the transparent shadows option turned off in Blender 4.1+. **Steps to reproduce** 1. Select from the top of Blender `File -> Defaults -> Load Factory Settings` 2. In the new default scene change the render engine to Cycles 3. Select the cude from the default scene and go to the material properties tab. 4. On the default material, you will find that transparent shadows is off. (The transparent shadows option can be found here in `Material Properties -> Settings -> Surface -> Transparent Shadows`) 5. Compare this to Blender 4.0 --- ``` Report "Light Path Node > Is Shadow Ray" is not working in Cycles in Blender 4.1+. The light is not passing through the glass material i created with "Light Path > Is Shadow Ray" in Cycles in 4.1+, whereas the same works in Blender 4.0, 4.0.1, and 4.0.2. ```

is-shadow-ray-not-working.blend

1.0 MiB

Lalit Kumar added the

labels 2024-04-18 04:29:52 +02:00

Alaska commented

2024-04-18 05:20:05 +02:00

Light Path Node > Is Shadow Ray is working just fine. But transparent shadows is turned off in your file when opened in Blender 4.1+, which means the Transparent BSDF isn't working. If you turn this setting back on, then everything works fine.

I ran some quick tests just to see if there was a bug causing transparent shadows to be turned off:

Is transparent shadows turned off by default in Blender 4.1.1? - Kind of (The default material in the startup scene has transparent shadows turned off in Blender 4.1.0+, but not in 4.0.2, meaning that if you re-used this material to create your scene, then you would get different results from older versions of Blender)
Does Blender 4.1.1 turn off transparent shadows when you open a Blender 4.1.1 file? - No
Does Blender 4.1.1 turn off transparent shadows when you open a Blender 4.0.2 file? - No

Is there anything else you can think off that's causing transparent shadows to be turned off in your file without you actively turning it off?

`Light Path Node > Is Shadow Ray` is working just fine. But transparent shadows is turned off in your file when opened in Blender 4.1+, which means the Transparent BSDF isn't working. If you turn this setting back on, then everything works fine. ![Location of transparent shadow option.jpg](/attachments/da15a0b6-805a-47a5-a22f-3ee8c982e537) I ran some quick tests just to see if there was a bug causing transparent shadows to be turned off: - Is transparent shadows turned off by default in Blender 4.1.1? - Kind of (The default material in the startup scene has transparent shadows turned off in Blender 4.1.0+, but not in 4.0.2, meaning that if you re-used this material to create your scene, then you would get different results from older versions of Blender) - Does Blender 4.1.1 turn off transparent shadows when you open a Blender 4.1.1 file? - No - Does Blender 4.1.1 turn off transparent shadows when you open a Blender 4.0.2 file? - No Is there anything else you can think off that's causing transparent shadows to be turned off in your file without you actively turning it off?

Location of transparent shadow option.jpg

82 KiB

Alaska added

and removed

labels 2024-04-18 05:20:26 +02:00

Alaska changed title from ~~"Light Path Node > Is Shadow Ray" is not working in Cycles in Blender 4.1+~~ to Blender 4.1+ defaults to transparent shadows off on default material

2024-04-18 05:20:57 +02:00

Alaska commented

2024-04-18 05:31:25 +02:00

This issue was likely introduced with 6d0b5e2ace

This issue was likely introduced with 6d0b5e2ace9830eace00fb2eeee080116b8c2e6d

Lalit Kumar commented

2024-04-18 06:14:08 +02:00

Thanks for showing what was causing the issue, and the fix. But Blender 4.1+ does turn off transparent shadows when you open a 4.0.2 file. And it's also turned off for new materials in 4.1+. So there is clearly an issue. Or this should be highlighted in 4.1 Release Notes, Videos, and Blender Manual.

Alaska commented

2024-04-18 08:18:41 +02:00

But Blender 4.1+ does turn off transparent shadows when you open a 4.0.2 file. And it's also turned off for new materials in 4.1+.

I can not reproduce this issue. Maybe there's some configuration issue on your end that's causing this?

Can you try loading factory settings then trying the various steps (opening a Blender 4.0.2 file, and creating new materials). If the results you get with factory settings is different from what you observe without it, then there is a configuration issue somewhere.

To load factory settings, select from the top of Blender File -> Defaults -> Load Factory Settings.

I have attached a video demonstrating my obvservations of these tests.

> But Blender 4.1+ does turn off transparent shadows when you open a 4.0.2 file. And it's also turned off for new materials in 4.1+. I can not reproduce this issue. Maybe there's some configuration issue on your end that's causing this? Can you try loading factory settings then trying the various steps (opening a Blender 4.0.2 file, and creating new materials). If the results you get with factory settings is different from what you observe without it, then there is a configuration issue somewhere. To load factory settings, select from the top of Blender `File -> Defaults -> Load Factory Settings`. I have attached a video demonstrating my obvservations of these tests.

Demonstration of working transparent shadow setting.mp4

2.8 MiB

Lalit Kumar commented

2024-04-18 14:04:49 +02:00

I’m also not able to reproduce the issue. But I created the original test file I shared in 4.1.1, with transparent shadows off by default in glass material, producing incorrect result. But if you open the same file in 4.0.2 then the transparent shadows get turned on producing correct result.

All I can share now are blend files created in 4.0.2 with a ‘linked’ glass material to reproduce the issue, which is how I work in real projects.

I’m also not able to reproduce the issue. But I created the original test file I shared in 4.1.1, with transparent shadows off by default in glass material, producing incorrect result. But if you open the same file in 4.0.2 then the transparent shadows get turned on producing correct result. All I can share now are blend files created in 4.0.2 with a ‘linked’ glass material to reproduce the issue, which is how I work in real projects.

Transparent-shadows-are-off-in-4.1.blend

988 KiB

glass.blend

1.1 MiB

Alaska commented

2024-04-18 14:40:22 +02:00

But I created the original test file I shared in 4.1.1, with transparent shadows off by default in glass material, producing incorrect result. But if you open the same file in 4.0.2 then the transparent shadows get turned on producing correct result.

This is a quirk of the Blender versioning system and is not considered a bug for Blender 4.0.2/4.1.1.

But it may be a bug in Blender 3.3.X or 3.6.X, I will need to check that.

> But I created the original test file I shared in 4.1.1, with transparent shadows off by default in glass material, producing incorrect result. But if you open the same file in 4.0.2 then the transparent shadows get turned on producing correct result. This is a quirk of the Blender versioning system and is not considered a bug for Blender 4.0.2/4.1.1. But it may be a bug in Blender 3.3.X or 3.6.X, I will need to check that.

Lalit Kumar commented

2024-04-18 17:33:02 +02:00

Please place the two blend files I shared above in a folder and link the glass material from ‘glass.blend’ to the glass material on Glass-Pane object in ‘Transparent-shadows-are-off-in-4.1.blend’ in 4.0.2 and save the file. Notice that transparent shadows are on in glass material in both files in 4.0.2. Then open these files with 4.1.1 to see the state of transparent shadows. It’s turned on in 'glass.blend', but is off in ‘Transparent-shadows-are-off-in-4.1.blend’, producing incorrect result and causing the original issue. To fix it, you’ve to save the 'glass.blend' with 4.1.1. So thanks again for showing the fix.

And why transparent shadows are turned off for default material in 4.1+ whereas it was on in earlier versions?

Please place the two blend files I shared above in a folder and link the glass material from ‘glass.blend’ to the glass material on Glass-Pane object in ‘Transparent-shadows-are-off-in-4.1.blend’ in 4.0.2 and save the file. Notice that transparent shadows are on in glass material in both files in 4.0.2. Then open these files with 4.1.1 to see the state of transparent shadows. It’s turned on in 'glass.blend', but is off in ‘Transparent-shadows-are-off-in-4.1.blend’, producing incorrect result and causing the original issue. To fix it, you’ve to save the 'glass.blend' with 4.1.1. So thanks again for showing the fix. And why transparent shadows are turned off for default material in 4.1+ whereas it was on in earlier versions?

Alaska commented

2024-04-19 05:16:44 +02:00

Please place the two blend files I shared above in a folder and link the glass material from ‘glass.blend’ to the glass material on Glass-Pane object in ‘Transparent-shadows-are-off-in-4.1.blend’ in 4.0.2 and save the file. Notice that transparent shadows are on in glass material in both files in 4.0.2. Then open these files with 4.1.1 to see the state of transparent shadows. It’s turned on in 'glass.blend', but is off in ‘Transparent-shadows-are-off-in-4.1.blend’, producing incorrect result and causing the original issue. To fix it, you’ve to save the 'glass.blend' with 4.1.1. So thanks again for showing the fix.

And why transparent shadows are turned off for default material in 4.1+ whereas it was on in earlier versions?

I can confirm this behaviour and I do believe it's a bug.

> Please place the two blend files I shared above in a folder and link the glass material from ‘glass.blend’ to the glass material on Glass-Pane object in ‘Transparent-shadows-are-off-in-4.1.blend’ in 4.0.2 and save the file. Notice that transparent shadows are on in glass material in both files in 4.0.2. Then open these files with 4.1.1 to see the state of transparent shadows. It’s turned on in 'glass.blend', but is off in ‘Transparent-shadows-are-off-in-4.1.blend’, producing incorrect result and causing the original issue. To fix it, you’ve to save the 'glass.blend' with 4.1.1. So thanks again for showing the fix. > > And why transparent shadows are turned off for default material in 4.1+ whereas it was on in earlier versions? I can confirm this behaviour and I do believe it's a bug.

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Blender 4.1+ defaults to transparent shadows off on default material #120762