LinearTransformationScene in v0.17.3: Circumscribe() causes problems

[uwezi]

Description of bug / unexpected behavior

in the LinearTransformationScene using self.play(Circumscribe()) around a MathTex() object leaves non-VMobjetcs behind on the scene which prevent any matrix operation.

See also https://discord.com/channels/581738731934056449/1147643803956682802/1147643803956682802

Expected behavior

An animation like Circumscribe() should clean up after itself...

How to reproduce the issue

The code below reproduces the problem, aborting with

TypeError: All submobjects must be of type VMobject

Remove the comment before #self.moving_mobjects = [] and the code will execute correctly.

Code for reproducing the problem

class LinearTransformationSceneExample_02(LinearTransformationScene):
    def __init__(self):
        LinearTransformationScene.__init__(
            self,
            show_coordinates=True,
            leave_ghost_vectors=True,
            background_plane_kwargs={"x_range":[-4,4,0.5],"y_range":[-2.25,2.25,0.5],"x_length":14.22,"y_length":8},
            foreground_plane_kwargs={"x_range":[-8,8,0.5],"y_range":[-4.5,4.5,0.5],"x_length":2*14.22,"y_length":2*8}
        )

    def construct(self):
        matrix = [[1 / 2, 0], [0, -1 / 2]]
        matrix_tex = MathTex(r"\hat{S}_z = \begin{bmatrix} \frac{1}{2}\hbar & 0 \\ "
                             r"0 & -\frac{1}{2}\hbar \end{bmatrix}").to_edge(UL).add_background_rectangle()
        matrix_tex2 = MathTex(r"\theta = 2").to_edge(UR).add_background_rectangle()
        self.add_foreground_mobject(matrix_tex, matrix_tex2)

        self.add_transformable_mobject(Vector(self.background_plane.c2p(0.809, -0.5878), color=BLUE))

        self.play(Circumscribe(matrix_tex))
        #self.moving_mobjects = []

        self.apply_matrix(matrix)
        self.wait()     

System specifications

• happens on Windows 10 and Manimator