In the documentation for CompositorEffects, the needs_normal_roughness property (https://docs.godotengine.org/en/stable/classes/class_compositoreffect.html#class-compositoreffect-property-needs-normal-roughness) provides an example of how to access the normal_roughness texture from inside a glsl shader.
There's also a needs_separate_specular property. How do I access the corresponding texture from inside a glsl shader running as part of a CompositorEffect? I assume that I need to know the name of the texture (i.e. not "normal_roughness", but something else). Does anyone know what this is, or how to find it out?
