Energy particles flowing upwards (particle sysem or volume?)

[wonderwyrm]

So I want to create a sort of energy effect that involves small balls of energy that flow upwards and dissipate. To put it in context we have a large ball of energy that sits above a large hole, the energy from the floor floats upwards and dissipates to simulate the energy flowing into the ball.

Would I use a fog volume for this or a particle system?

Would someone be able to suggest a few tutorials on doing this or point me in a direction?

[jlhill17]

I would use a particle system. You can find documentation for it over on the UDN.