To make a different audio analogy: When they graph the input vs. the optimized control values, it looks a lot like the ringing artifacts of a low-pass filter. A

To make a different audio analogy: When they graph the input vs. the optimized control values, it looks a lot like the ringing artifacts of a low-pass filter. A low-pass filter removes high frequencies from an input signal. Since there are physical limits on how fast limbs can oscillate, maybe that’s part of what makes it look more natural.