Godot version

4.0.alpha (0393057)

System information

Fedora 34, GeForce GTX 1080 (NVIDIA 495.46)

Issue description

Radiance prefiltering looks good on the Vulkan Clustered backend, but it doesn't see the same improvements in the mobile backend (running with desktop default settings). Reverting #58177 restores filtering quality to what it was before in the Vulkan Mobile backend (although the Real-Time filter mode still exhibits the issue).

Vulkan Clustered

High Quality	Real-Time

Vulkan Mobile

High Quality	Real-Time

Vulkan Mobile (with #58177 reverted)

High Quality	Real-Time

Steps to reproduce

• Use an HDRI panorama sky from a website such as Poly Haven.
• Add meshes with rough materials to the scene.
• Switch to the Vulkan Mobile backend in the project settings (search for back end).
• Restart the editor.

Minimal reproduction project

tests/3d/test_pbr_radiance_high_quality.tscn and tests/3d/test_pbr_radiance_real_time.tscn in https://github.com/Calinou/godot-rendering-tests