Controlling rotorcraft to fly precisely through multiple, irregularly, and closely spaced waypoints is a common and practical mission. However, finding an optimal trajectory for this kind of mission is quite challenging. Usability of traditional approaches such as inverse control or direct methods to this kind of problem is limited because of either limitation on the specification of the constraints or requirement of extensive computation time. This paper proposes a method that can easily compute the full trajectory and control history for rotorcraft to pass through waypoints while satisfying other general constraints of states such as velocities and attitudes on each waypoint. The proposed method is applied to rotorcraft guidance problems of slalom and linear trajectory in the middle of general curved trajectory. The algorithm is test for various situations and demonstrates its usability.