area.setSize( 4d, 4d );
area.startingTime = instance.time;
double angle = ball1.directionTo( ball2 ) + 0.5d * Math.PI;
for( int n = 1; n <= particlesQuantity; n++ ) {
Sprite particle = new Sprite();
particle.jumpTo( area );
particle.angle = angle + Service.random( -Math.PI / 12d, Math.PI / 12d ) + ( n % 2 ) * Math.PI;
particle.setDiameter( Service.random( 0.2d, 0.6d ) );
particle.velocity = Service.random( 0.5d, 3d );
area.particles.addLast( particle );
}