** Tested only in ToonBoom Harmony 14 **
This rig has a ball drawing with a shadow that automatically shrinks and becomes more transparent as the ball moves away from the shadow. The shadow also follows the ball movement in x and z axis. It still allows some manual reposition if needed. In the file there's a note with instructions on how to use it and how to replicate it for another object.
There's a video to show how it works:
I forgot to mention in the video that there's an easy way to use the shadow in another rig:
Select everything in the ball rig plus the 'ball-P' and duplicate them. Use the 'ball-P' as the new master peg of your rig and move the shadow drawing to match the new object/character.