The tracking operation is a typical case of an operation that uses existing objects to extract additional information. Tracking is covered more fully as a specific topic in the Tracking in arivis Pro article, but for now let's look at how an operation like this works.

The first parameter in all these operations that use existing objects is the tag for the objects to be modified. This tag must belong to objects that were created or imported into the pipeline. So, for example, our Blob Finder operation created objects and tagged them "Vesicles" and so we can select this tag as an input for the objects we want to track:

Like the Segmentation operation that created the object applies a tag to every object it created, these Use Objects operations also apply a tag to every object they modify. In the case of tracking in particular, it applies two different to the segmented objects that it tracked, and the track type object that it creates from each group of tracked objects.