thanks, i think i might be able to use that link to help.
I Do not want the line to fade. I would like it to behave like this.
Button A - plays animation of dot moving across screen, and draws a line (trail) of the path the ball is taking. (this line only goes away when another button is pushed)
Button B - Plays animation of the same dot taking a different path across screen while drawing the new path.
godot1776 | 2017-02-02 18:56
Custom drawing with _draw() is what you are looking for then