public void addForce(THREE.Vector3 force)
{
THREE.Vector3 a = force.clone();
a.multiplyScalar(invMass);
acc.add(a);
}
public Particle(double m, THREE.Vector3 pos)
{
position = pos.clone();
previous = pos.clone();
original = pos.clone();
acc = new THREE.Vector3(0, 0, 0);
mass = m;
invMass = 1.0 / mass;
}