@jpfjord "Set Angle over life time" should work. Assuming your particles have a life time (are not immortal), Else you can use "Set Angle over age" (immortal particles can age). For the angle, also pay attention to the axis you want your rotation about (For billboard it will generally be Z axis). We also have an attribute called "Angular Velocity", so you can specify a rotation speed per axis and at each update, particle angles will be integrated based on their angular velocity. If you still have issues getting this work, maybe a screen of your graph can help.