Diffuse Light pass not working as expected in 3.2 Eevee with 'shader to RGB' #100166

New Issue

Kyle Smart · 2022-08-03T12:38:33+02:00

Kyle Smart commented

2022-08-03 12:38:33 +02:00

System Information
Operating system: macOS-12.4-x86_64-i386-64bit 64 Bits
Graphics card: Apple M1 Apple 4.1 Metal - 76.3

Blender Version
Broken: version: 3.2.1, branch: master, commit date: 2022-07-05 15:44, hash: a2d59b2dac
Worked: 3.1
Affected by 80859a6cb2

Short description of error
Diffuse light pass does not work on shaders using 'shader to rgb' node and just comes back blank. it will severely limit the use of compositor with simple NPR style shaders if so. Unless there is a new approach to this node setup I'm not aware of. Other NPR shaders with a colour component also get lost when going between passes.

Exact steps for others to reproduce the error
Attached blend file has simple toon shader. When going from 'combined' pass to the 'diffuse light' pass all information is lost. Not able to isolate the passes that makes up the 'combined' pass for compositing etc.

3.2shadertest.blend

**System Information** Operating system: macOS-12.4-x86_64-i386-64bit 64 Bits Graphics card: Apple M1 Apple 4.1 Metal - 76.3 **Blender Version** Broken: version: 3.2.1, branch: master, commit date: 2022-07-05 15:44, hash: `a2d59b2dac` Worked: 3.1 Affected by 80859a6cb2 **Short description of error** Diffuse light pass does not work on shaders using 'shader to rgb' node and just comes back blank. it will severely limit the use of compositor with simple NPR style shaders if so. Unless there is a new approach to this node setup I'm not aware of. Other NPR shaders with a colour component also get lost when going between passes. **Exact steps for others to reproduce the error** Attached blend file has simple toon shader. When going from 'combined' pass to the 'diffuse light' pass all information is lost. Not able to isolate the passes that makes up the 'combined' pass for compositing etc. [3.2shadertest.blend](https://archive.blender.org/developer/F13333543/3.2shadertest.blend) ![3.2 basic toon - diffuse light pass.png](https://archive.blender.org/developer/F13333544/3.2_basic_toon_-_diffuse_light_pass.png) ![3.2 basic toon - combined pass.png](https://archive.blender.org/developer/F13333545/3.2_basic_toon_-_combined_pass.png) ![3.1 basic toon - diffuse light pass.png](https://archive.blender.org/developer/F13333546/3.1_basic_toon_-_diffuse_light_pass.png)

Kyle Smart commented

2022-08-03 12:38:33 +02:00

Added subscriber: @Smart_Kyle

Pratik Borhade commented

2022-08-03 12:42:16 +02:00

Added subscriber: @PratikPB2123

Pratik Borhade commented

2022-08-03 13:05:25 +02:00

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

Pratik Borhade commented

2022-08-03 13:05:25 +02:00

Thanks for the report. I'm able to replicate this. Will search the affecting commit.

Pratik Borhade commented

2022-08-03 13:28:45 +02:00

Added subscriber: @fclem

Pratik Borhade commented

2022-08-03 13:28:45 +02:00

Broken since: 80859a6cb2
@fclem ^

Broken since: 80859a6cb2 @fclem ^

Clément Foucault commented

2022-08-03 15:55:36 +02:00

Added subscriber: @Jeroen-Bakker

Clément Foucault commented

2022-08-03 15:55:36 +02:00

The old behavior was incorrect. It is now considered as emission as it should have been.
However, it doesn't even work as the emission pass is completely black. That is the real bug to me. I guess that for the emission pass the diffuse shaders are not evaluated (which make sense). Unfortunately, I don't see that being fixed for EEVEE. Maybe @Jeroen-Bakker has an opinion on this.

Note that it is already working as intended in EEVEE-Next.

The old behavior was incorrect. It is now considered as emission as it should have been. However, it doesn't even work as the emission pass is completely black. That is the real bug to me. I guess that for the emission pass the diffuse shaders are not evaluated (which make sense). Unfortunately, I don't see that being fixed for EEVEE. Maybe @Jeroen-Bakker has an opinion on this. Note that it is already working as intended in EEVEE-Next.

Kyle Smart commented

2022-08-03 16:19:13 +02:00

Ah I see, that's maybe unfortunate, as being able to separate out diffuse colour, diffuse light and specular etc for the compositor on more stylised shaders opened up a lot more options for NPR workflows and it doesn't seem like there's a good alternative with everything being pumped through 1 pass (emission), especially for any screen space effects. For instance something as simple as drawing a 5px line around shadows on an NPR shader is possible with 3.1 EEVEE and a simple compositor node graph on the diffuse light pass.

Hopefully the shadow pass itself on EEVEE next will make up for this, as I'm assuming it will probably be cleaner, but still does not seem as flexible as having specific passes + more parity between NPR and realistic shaders.

Thank you for the reply :)

Ah I see, that's maybe unfortunate, as being able to separate out diffuse colour, diffuse light and specular etc for the compositor on more stylised shaders opened up a lot more options for NPR workflows and it doesn't seem like there's a good alternative with everything being pumped through 1 pass (emission), especially for any screen space effects. For instance something as simple as drawing a 5px line around shadows on an NPR shader is possible with 3.1 EEVEE and a simple compositor node graph on the diffuse light pass. ![4b3fd2e6-5e1f-42ad-afd7-5ba3e6113fa0_rw_1200.gif](https://archive.blender.org/developer/F13334025/4b3fd2e6-5e1f-42ad-afd7-5ba3e6113fa0_rw_1200.gif) Hopefully the shadow pass itself on EEVEE next will make up for this, as I'm assuming it will probably be cleaner, but still does not seem as flexible as having specific passes + more parity between NPR and realistic shaders. Thank you for the reply :)

Philipp Oeser removed the

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Diffuse Light pass not working as expected in 3.2 Eevee with 'shader to RGB' #100166