Welcome to TVPaint Community forums !

I'm doing a simple ball bouncing. The first drawing with the ball at the highest point, and the last frame with the ball at the lowest point on the ground.
I'm setting the Ping Pong function to make the ball bounce on it's own, but it's not working. It's simply playing straight ahead and then popping back to the first frame and playing straight ahead.

What am I doing wrong?

If you have only one layer, then the animation playback will only play the frames contained in that layer. Then the post-behviour ping-pong will not be played.
You need to create another layer which ends where you want the animation to stop and start over.
The animation playback will play until the farthest image of your longest layer. Unless you place a Mark Out before then.

The other option is to use the in layer "repeat Images" function rather than the tag at the end of the layer. I find this is really useful for keeping a project tidy too...

https://www.tvpaint.com/doc/tvp11/index ... eat-images

Thanks Melanie and Daninski!

Melanie - Thanks for this.