Making things collide involves timing the trajectory of the elements in a shot, aiming of the trajectory and it’s timing and then adjusting these until the collision occurs. To do this we usually use Arduino, MAX MSP or a StopShot.
Beer and foam collide
A great example of making a collision is a CASIO test we made for the last Duvel commercial with Stef Viaene. By gradually adjusting the power of a pump and a magnetic release we were able to effect a collision of foam and beer.
On the right a take from the Duvel shoot… below the workshop test made on the CASIO