Refraction is broken in Compatibility renderer

[lw64]

Tested versions

I use 4.4.1 stable.

System information

Arch Linux

Issue description

There is no refraction.

one thing I think might be an issue is that the screen texture doesnt have mipmaps, but thats not all...

Steps to reproduce

Have a scene with one mesh with standard material, enable refraction and set albedo alpha to 0.3.

Minimal reproduction project (MRP)

currently I dont have one but should be easy to reproduce.

[AThousandShips]

Please provide an MRP to make this easier to test and fix:

• A small Godot project which reproduces the issue, with no unnecessary files included. Be sure to not include the .godot folder in the archive (but keep project.godot).
• Having an MRP is very important for contributors to be able to reproduce the bug in the same way that you are experiencing it. When testing a potential fix for the issue, contributors will use the MRP to validate that the fix is working as intended.
• Drag and drop a ZIP archive to upload it (max 10 MB). Do not select another field until the project is done uploading.
• Note for C# users: If your issue is not C#-specific, please upload a minimal reproduction project written in GDScript. This will make it easier for contributors to reproduce the issue locally as not everyone has a .NET setup available.

There isn't enough clear detail here, please add complete system information and an MRP

[lw64]

view in mobile renderer:

view in compatibility renderer:

reproducer project:

reproducer.zip

[llama-nl]

I not sure what about the issue is, but the behavior is different in this two renderer. This is not clear that is expected.

[Calinou]

I can reproduce this on 4.5.dev be3ecae (Linux + NVIDIA). I'm not sure what's causing this, considering we removed all is_low_end() checks that disabled some BaseMaterial3D features with #51967 and #89528. Changing the refraction strength, texture, roughness or normal map doesn't seem to affect it at all.