smooth animation following a random path in real time

Question

So, I'm toying around with an augmented reality game. I'm using computer vision to track a particular object, which works reasonably well. I'm trying to animate something that basically follows that object around on screen.

This has proven pretty hard. The tracked location of the object is very jittery. I've tried to smooth it out by setting a threshold under which we don't bother moving the sprite, but this leads to jumpy animation rather than jittery. I want the sprite to follow the tracked object in close to real time, so aggregating movement over a lot of frames to get smooth results isn't a great option for me.

Are there any techniques I could use in this case that might help smooth things out?

Answer 1

Springs using Hooke's Law can help here, they are basically a low-pass filter, filtering out the high frequency jittering. One end of the spring is connected to the following object, the other end is connected to its (jittering) target position.

Here is a gafferongames article about them.

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A simpler solution might be to use an easing function to make the object follow the jittering target-position smoother.