Vulkan: Environment Ao Channel Affect property has no effect and should be removed

[Calinou]

Related to #43957.

Godot version

4.0.dev (536757b)

System information

Fedora 34, GeForce GTX 1080 (NVIDIA 470.74)

Issue description

The SSAO Ao Affect property no longer has any effect, but it's still present in WorldEnvironment. Quoting from #45023:

-SSAO ao affect is gone because this confused users, min(ao,ssao) now used, should work in most cases.

I tried to remove this property in https://github.com/Calinou/godot/tree/remove-ao-channel-affect but didn't succeed yet.

By the way, the Ssao > Light Affect property in WorldEnvironment also seems to have no effect. Only the BaseMaterial3D ambient occlusion Light Affect property seems to have an effect on AO appearance, on both the AO map and SSAO. This is likely a bug though, as I'd expect the material property to only influence the AO map, not SSAO.

Steps to reproduce

• Create a MeshInstance with a BoxMesh and StandardMaterial3D.
• Assign an ambient occlusion map to the material.
• Enable SSAO in WorldEnvironment.
• Adjust Ao Channel Affect in WorldEnvironment, and notice how it has no effect on the scene.

Minimal reproduction project

test_ssao_ao_affect.zip

[WickedInsignia]

I've noticed that AO doesn't work as expected on Standard Material. If the Light Affect slider is at 0, the AO map doesn't affect the appearance of the material even in the absence of direct light. Light Affect at 1 does what it should though.
Let me know if we need a unique bug report for this, but the issue was close enough to this one for me to not risk the duplicate.

[Calinou]

I've noticed that AO doesn't work as expected on Standard Material. If the Light Affect slider is at 0, the AO map doesn't affect the appearance of the material even in the absence of direct light. Light Affect at 1 does what it should though. Let me know if we need a unique bug report for this, but the issue was close enough to this one for me to not risk the duplicate.

I recall seeing this issue in 3.x, but not in 4.x. Do you have SSAO or SSIL enabled?

Either way, this should be tracked in a separate issue, so please open an issue with a minimal reproduction project attached.