trait OrientedSurfaceViscosity is Physics.Interactions.SurfaceContact.Traits.SurfaceViscosity:
    .doc: """
Extends the SurfaceViscosity trait and introduces
a secondary viscosity in the secondary direction,
defined by an OrientedFricion trait

works with Physics.Interactions.Dissipation.DefaultDryFriction with OrientedFriction

"""

    secondary_viscosity is Real
