show object trace in Java3D?

[Kevin]

Hello,

Does anyone know how to do this in Java 3D:

suppose there is a ball bouncing around in the Java 3D world.

How to show the trace of this ball in this Java 3D world as well?
(suppose we need to show the trace up to last 10 seconds)

What I mean is, suppose "O" is the ball. Without trace, if the ball
moves from position A to B, it looks like:

Pos A Pos B
O

With trace, it looks like:
Pos A Pos B
_______________________
_______________________O

where "_______" stays in the 3D world like a trace / shadow.
_______

Hope I get my question clear.

The only way I can think of is, as the ball moves, we create many
exactly the same ball ojects and put them in the 3D world along the
path the ball moves. But this sounds not efficient.

Thanks a lot.