ProximitySensor

  ProximitySensor { 
      exposedField SFVec3f    center      0 0 0    # (-,)
      exposedField SFVec3f    size        0 0 0    # [0,)
      exposedField SFBool     enabled     TRUE
      eventOut     SFBool     isActive
      eventOut     SFVec3f    position_changed
      eventOut     SFRotation orientation_changed
      eventOut     SFTime     enterTime
      eventOut     SFTime     exitTime
    }