Control theory text.
'PID Control The "PID" in "PID Control" stands for "Proportional, Integral, Derivative". These three terms describe the basic elements of a PID controller.'
'PID Control The "PID" in "PID Control" stands for "Proportional, Integral, Derivative". These three terms describe the basic elements of a PID controller.'
But, I had been writing smooth movement and animation for years and never needed a PID controller before, or implemented one accidentally. In fact using animation smoothing is what got me into trouble with the AI driving. In retrospect, I would call basic animation smoothing a “P” controller, you do something in proportion to your goal. To make it smoother, you just turn down the proportion. I tried making the AI driver use a P-controller to steer in order to stay on the optimal racing line.
When you introduce a delay in the system between input and reaction - which is what happens when your car is subject to physics, and when steering changes are rate limited - this is when animation smoothing (P-controller) causes a really surprising behavior. The lower you turn down the P value, the more unstable the system becomes. I was confused at first... why would reducing the input cause the system to go from oscillating to divergent? But when someone suggested reading up on PID controllers, it all made sense, and I was a bit stunned that I hadn’t even heard about them during my undergrad CS years.