Godot version

v4.1.dev1.official [db13026]

System information

Windows 10, Compatibility, NVIDIA GeForce GTX 1050 Ti (528.24)

Issue description

Setting the blend mode to something besides mix behaves the same as mix. This is the same whether is a ShaderMaterial or a StandarMaterial3D.

I think this should have been fixed by #75968 unless I misunderstood the PR, and it does seem to be included in this version (4.1 dev1). It does work if you set the Depth Draw Mode to Never though.

Steps to reproduce

• Add a MeshInstance3D with a mesh of any type
• Add a StandarMaterial3D
• Set the blend mode to add (or any other than mix)
• It won't work unless you set the depth draw mode to Never

Minimal reproduction project

BlendAdd.zip