Boids 3D - Creating Boundaries - Walls

Im using the Boids 3D Pluging for a lot of projects lately and must say that its fun to use :)

boids-3d

So here is my question:

Im trying to create boundaries which can not be breached by my flock. In other words: Walls.

The flocking system itself works with a Flockingradius, but the flock is still able to leave these boundaries depending on the position of their target and their velocity. I need something that would trap them inside, like in a fishtank for example.

Using bullet physics didnt make any sense since the 2 systems cant interact with each other.

Mapping the output values is a solution, but it would distort the movementspeed to much.

My first solution for this has been creating a huge spread of enemies that form the walls that trap my flock.

It does work, depending on the Velocity of my flock, but occasionally a few Boids escape.

Is there any solution for this im not thinking of?

Like i have said my solution does work, but it is very limited and tricky. I wouldnt want to waste time on perfecting it if there are better ways. :)