drawing a line in motion

this seems to be an easier / more accure way to trace a clubhead, rather than trying to create the curve with the bezier tool which i'm not proficient at.
the video explains everything except how he created the circle particle. i can't seem to find a circle particle in particle images library.

That's actually an excellent way to do it!

He just drew a Circle with the Circle drawing tool. Then made that into an Emitter.

when i try this and add the animation the circle just moves laterally. it doesn't follow the clubhead on the golf club.
how to I get it to follow the clubhead?
thanks for the reply

You have to track it.
help.apple.com/motion/mac/5.4/#/motn18191fa3

How would one change the dashes from having 90-degree edges, to having rounded edges?

Draw line with Bezier, select Airbrush, choose 'Dash Medium'' as Style, apply Write-On Behav …