When applied to a field/property of type PhysicsMask, the field/property drawer will not be display it as PhysicsLayers. Instead, the field/property will be displayed as bit numbers only i.e. a raw 64-bit mask allowing each bit to be (de)selected. This is only used when physics layers are active (see _usePhysicsLayers ).

[AttributeUsage(AttributeTargets.Property|AttributeTargets.Field, Inherited = true, AllowMultiple = false)]public class PhysicsMask.ShowAsPhysicsMaskAttribute : PropertyAttribute