成员的完整列表，这些成员属于 _vrpn_TRACKERTRACKER2ROOMCB,包括所有继承而来的类成员

msg_time (定义于 _vrpn_TRACKERTRACKER2ROOMCB)	_vrpn_TRACKERTRACKER2ROOMCB
tracker2room (定义于 _vrpn_TRACKERTRACKER2ROOMCB)	_vrpn_TRACKERTRACKER2ROOMCB
tracker2room_quat (定义于 _vrpn_TRACKERTRACKER2ROOMCB)	_vrpn_TRACKERTRACKER2ROOMCB