Vulkan: SDFGI reflect wrong with depth texture read

[ywaby]

Godot version

4.0 dev

System information

debian stable, GTX1050TI, vulkan

Issue description

SDFGI reflection is not right with reading depth texture in shader.

Steps to reproduce

1. enable sdfgi.
2. read depth texure in shader.

Minimal reproduction project

Uploading godot.zip…

[BenjaminNavarro]

It seems to me that SDFGI is not the only one impacted by reading DEPTH_TEXTURE. I noticed that VoxelGI also produces different results whether the depth texture is read or not.

[ODtian]

Any update? it seems still a bug in 4.0.1.stable.

[Calinou]

This is not a bug. Reading depth texture in a shader makes the material transparent by design. For performance reasons, SDFGI does not support sharp reflections on transparent materials, only rough reflections (the same as the ones you get with roughness >= 0.2).

A bug with VoxelGI reflections on transparent materials was fixed in 4.0.rc: #69783