I made this program to simulate in real-time the trajectory of a charge held by a crane. The 2D view of the crane is useful to set the different control points where the charge must change its path spatially or temporally. The speed/acceleration of the crane is variable and the charge can move along the x, y and z axis. The 3D view is useful do display the path in 3D. This software uses java draw for the interactive 2D view of the crane and J3D for the 3D view of the simulation.