Fix shader doc comments to show up for instance uniforms

[Chaosus]

• Closes GDShader documentation comments for per-instance uniform does not show in inspector #95583

[jsjtxietian]

Code looks good to me. But this only works when the shader is at material override, not when the shader is set to the mesh instance itself.

[jsjtxietian]

Shader instances only show when shader set as material override.

Using the shader provided in the issue, set the shader to the mesh instance:

Set the shader to material override:

[Chaosus]

Check again, I think I've fixed it.

[jsjtxietian]

Check again, I think I've fixed it.

It did not work when the shader is draged to mehs instance's material field.

The surface_override_materials has one element but is null:

[Chaosus]

What do you mean by mesh instance's material field ? Surface material override property? If so my last commit fixed it, and it's working for myself, you need to reload a scene, maybe.

[jsjtxietian]

I mean here, the surface material override property work fine :

[Chaosus]

@jsjtxietian Ok, I understood what you mean (A material property of a PrimitiveMesh), I think I've fixed it now

[jsjtxietian]

Tested locally, works as expected.