I am writing an engine to do 3D rotations and movements in 3D space. I’m using quaternions to do the rotations based on yaw pitch and roll and have gotten my ship in space to rotate fine. However what I want to do is to have it move in the direction of the final angle. Only problem is all I have to work with is just one angle. How can I use this to set up a direction to tell my plane to move in? Thanks for the help.