I am doing a juggling project and need to track the motion of 3 balls (red, yellow, and white). So far, I've been really liking Blender's UI for motion tracking. I have manually tracked an individual ball for 1800 frames and am wondering if there is a better way of going about this. The balls are regularly occluded and sometimes go out of the camera's view, so is there a way of tracking each ball using one track per ball for the entire duration of the video? I also would like to export the curves from the tracking to a graph so that I can present my data. What are some methods I can use?
When an object disappears momentarily form the scene (either it goes out of frame and comes back later, or is occluded by other objects) you can track up to the point where it becomes untrackable, then add a new tracker for other sections of the video when the object reappears. Then just select the trackers and merge them with the Join Track button
That way Blender knows that is not dealing with a new object, but the same one.
Once you are done traking your objects go to the solve section/geometry and select "Link Empty to Track".
That will create empties on the 3D environment that follow the movement set by the trackers. From there you should be able to create the graphs you are after.