The priority for mixing the PhysicsShape.friction properties when two shapes come into contact. If the priority of one shape is higher than the other shape then the higher priority PhysicsShape.SurfaceMaterial.frictionMixing will be used. If the priority of both shapes are the same then simply the higher enumeration value of PhysicsShape.SurfaceMaterial.MixingMode from both shapes will be used.

public ushort frictionPriority { readonly get; set; }