As my pack aims to be fully LabPBR compliant, here’s an example of what can be achieved with such a format.
This composite screenshot was achieved with the awesome Kappa Shader from shader developer Rre36 : https://rre36.github.io/glsl_kappa/
Porosity affects how materials absorb water when it’s raining, and how they react to drying out.
Center is wet, porosity effect at maximum. Borders are dry.