@Override
    public void reactOnCollision(ElementField element, CollisionMan.TYPE type) {
        if (_faced == null || !_faced.equals(element)) {
            if (element.mass() == MASS.INF_MASS) {
                collideWithUnmovableElement(element, type);
            } else {
                collideWithMovableElement(element, type);
            }
            _faced = element;
        }
    }