3D Read Screen Shaders didn't work well with SSR

[NiJingzhe]

Tested versions

• Reproduce in Godot 4.1 stable， Godot 4.2.1 stable，Godot 4.3-dev5

System information

Windows 11 - Godot v4.1.0 stable - Vulkan (Forward+) - dedicated !

Issue description

I create a Water ( a plain mesh) in my test_map.tscn, using ShaderMaterial to make refraction effect. But when I put test_map into MainWorld.tscn (With SSR open in Environment), water cannot correctly read screen texture and everything under water surface became compeletely invisible

• Without SSR

• SSR opened

Steps to reproduce

In MRP, you just need to switch the SSR checkbox and you can see the problem.

Minimal reproduction project (MRP)

MRP.zip

[NiJingzhe]

shader code is include in MRP : )

[AThousandShips]

You didn't wait until the MRP uploaded, please edit and try again, make sure you wait until it's been uploaded

[AThousandShips]

Also please try with a supported version, like 4.1.3, or 4.2.1

[NiJingzhe]

Got it

[NiJingzhe]

Also please try with a supported version, like 4.1.3, or 4.2.1

4.2.1-stable and 4.3-dev5 have been tested and both of them can reproduce this problem : )

[ttencate]

Screen-reading shaders go through the transparent pipeline, which is sorted after all opaque geometry has been rendered. It has to be this way, otherwise you wouldn't have a complete screen texture to read from. So essentially, a screen-reading shader is treated as a transparent material.

And currently, screen-space reflections cannot appear on transparent materials. There is an open proposal to address this: https://github.com/godotengine/godot-proposals/discussions/7274