// Applies an impulse based on a collision
private void CollisionResponse(PhysicsObject pm, PhysicsBox b)
{
// Find the normalized relative velocity
Vector3 relVel = pm.Velocity;
Vector3 norm = pm.Position - b.Position;
float nVel = Vector3.Dot(relVel, norm);
// Set velocity to halt movement
pm.Velocity = Vector3.zero;
// Restitution (bouncyness)
float e = 0.9f;
// Calculate impulse
float j = -(1 + e) * nVel;
j /= (pm.mass + b.mass);
Vector3 impulse = j * norm;
pm.AddImpulse(impulse);
}