I have an issue with a mechanic in a game I am working on. I attached a crude diagram I made in paint to help me explain my issue.

Blue Box - Dynamic Box

Black Box - Static Box

Red Arrow - Gravity

Yellow Arrow - Force from black box

Green Circle - Rang of Yellow Arrow

First diagram shows the blue box at rest being pushed down by gravity.

The second diagram shows what happens when the black box turns on it's opposing force.

The third diagram shows where I want the blue box to eventually come to a rest.

What currently happens is when the opposing force is kept on, the blue box goes to the highest point possible then falls all the way back down to black box and will continue doing that until the opposing force is turned off. I want the box to slowly level out and hover (like diagram three).

I am just looking for ideas on how you might handle it. Nothing I have come up with has worked.

P.S. - I am doing this in XNA using BEPUphysics engine.

velocity += acceleration * delta_time;

velocity = exp(-some_positive_constant * delta_time) * velocity + acceleration * delta_time;

I was thinking that the two forces acting on each other would cause a dampening to the oscillation, since when playing with magnets in real life they eventually came to a rest above the base magnet. I wasn't thinking about air resistance. I suppose if I took the same magnets in real life and put them in a vacuum they wouldn't stop either.

As for having a range on the magnetic field, I needed to do that in order to control how many magnets were acting on the player, otherwise it would result in quite a few game breaking bugs. Though I suppose if I had the magnets properly responding to distance it wouldn't be a problem...