It can come in handy:
-When trying to build an environment around your animatedcharacter for example.
-or to see how your animation flows instead of using the normal line trajectory.
-also to know the dimention that our charachter are moving in to build FumeFX container or other fx stuff.
It's based on Blob mesh so:
-It is advisable to check the best setting by creating a test abject and apply Blob mesh to it and see the approprite settings for your scene (size and resolution) and plug it into the script interface. Why I'm saying this because in case your mesh is heavy or you used a heigh frame rate it might take a long time.
-And also let your mesh have some segments, let's say you wanna track bones, so applying tesselate moddifier is good in this situation.
How it works:
-Select the object(s) you want to track.
-Set every how many frames the tracking should occur (everyframe or two.....)
-BlobSize: defines how much the mesh is going to expand around the character
-Resolution: The less the number the more mesh you are going to end up with (So be carefull here)
-And finally there is no harm in relaxing a bit.
Hit Create and the mesh will be created to cover your selected object on the whole timerange.