Charge.point not updated when moving it

[Viicos]

So whenever a Charge object is instanciated, the attribute point is set:

manim-physics/src/manim_physics/electromagnetism.py

Lines 16 to 40 in 70ab45a

	class Charge(VGroup):
	def __init__(
	self,
	magnitude: float = 1,
	point: np.ndarray = ORIGIN,
	add_glow: bool = True,
	**kwargs,
	) -> None:
	"""An electrostatic charge object. Commonly used for :class:`~ElectricField`.
	Parameters
	----------
	magnitude
	The strength of the electrostatic charge.
	point
	The position of the charge.
	add_glow
	Whether to add a glowing effect. Adds rings of
	varying opacities to simulate glowing effect.
	kwargs
	Additional parameters to be passed to ``VGroup``.
	"""
	VGroup.__init__(self, **kwargs)
	self.magnitude = magnitude
	self.point = point

but this attribute is not updated when using methods such as move_to or shift:

class Sample(Scene):
    def construct(self):
        charge = Charge()
        print(charge.point)
        charge.shift(UP)
        print(charge.point)
>>[0. 0. 0.]
>>[0. 0. 0.]

This implies some incorrect behaviour e.g. when using ElectricField.get_force_on_charge:

class Sample(Scene):
    def construct(self):
        charge_1 = Charge(add_glow=False)
        charge_2 = Charge(add_glow=False).shift(UP)
        field = ElectricField(charge_1)
        f = field.get_force_on_charge(charge_2)
        self.add(charge_1, charge_2, field, f)

Result

You can see here that the f vector is still located on the origin, where the charge_2 was previously located.

This happens because the code of the get_force_on_charge method is using the charge.point attribute L147:

manim-physics/src/manim_physics/electromagnetism.py

Lines 129 to 149 in 70ab45a

	def get_force_on_charge(self, charge: Charge, **kwargs) -> Vector:
	"""Returns a vector corresponding to the force
	of the electric field on the charge.
	"""
	p = charge.get_center()
	direction = np.zeros(3)
	for other_charge in self.charges:
	if other_charge == charge:
	continue
	p0, mag = other_charge.get_center(), other_charge.magnitude
	x, y, z = p - p0
	dist = np.linalg.norm(p - p0) ** 3
	if (x**2) > 0.01 or (y**2) > 0.01:
	direction += mag * np.array([x / dist, y / dist, 0])
	else:
	direction += np.zeros(3)
	length = (direction[0] ** 2 + direction[1] ** 2) ** 0.5
	vec_start = (
	Vector(direction / length * charge.radius).shift(charge.point).get_end()
	)
	return Vector(direction, **kwargs).shift(vec_start)

So maybe to fix this the methods moving the object such as shift, move_to, to_corner should be overrided? The thing is we can't be 100% sure that all the methods modifying the object's position have been taken into account. Maybe there's a more general way of fixing this.