I'm having difficulty trying to create a barage of arrows in flight using a particle system with an instance of a model arrow. I thought that using particles would allow me to randomise the flight of each individual arrow in the group through the influence of different fields. While I have more or less acheived this I'm really stuck on how to change the orientation of the individual arrows so that each is aligned with the path of its own flight (will point upward as it climbs, level off as it peaks and point downward as it decends) I've read various diffent posts relating to particle control and all I seem to manage is to make each arrow spin wildly as it arcs across the screen. Please help!!!
Set aimDirection to velocity in the particle instance attribute section of the particle shape. As long as your source object is oriented pointing down the positive X axis it will allign facing the direction the particle is moving. No fancy expressions are needed.