fix VShowPassingFlash index out of bounds issue

[germanzhu]

Motivation

Animation VShowPassingFlash often encounters an IndexError: index 0 is out of bounds for axis 0 with size 0. for example:

from manimlib import *

class Video(Scene):

    def construct(self):
        s = TexText(r"A",template="tex")
        self.play(ShowCreation(s))
        self.play(VShowPassingFlash(s))

The error message is as follows: File "test.py", line 9, in construct self.play(VShowPassingFlash(s)) File "manimlib/scene/scene.py", line 405, in wrapper func(self, *args, *kwargs) File "manimlib/scene/scene.py", line 661, in play self.begin_animations(animations) File "manimlib/scene/scene.py", line 616, in begin_animations animation.begin() File "site-packages/manimlib/animation/indication.py", line 227, in begin super().begin() File "manimlib/animation/animation.py", line 79, in begin self.interpolate(0) File "manimlib/animation/animation.py", line 143, in interpolate self.interpolate_mobject(alpha) File "manimlib/animation/animation.py", line 155, in interpolate_mobject self.interpolate_submobject(mobs, sub_alpha) File "manimlib/animation/indication.py", line 247, in interpolate_submobject submobject.set_stroke(width=widths gaussian) File "manimlib/mobject/types/vectorized_mobject.py", line 207, in set_stroke data['stroke_width'][:, 0] = resize_with_interpolation( File "manimlib/utils/iterables.py", line 109, in resize_with_interpolation return np.array([ File "manimlib/utils/iterables.py", line 110, in (1 - a) nparray[lh] + a * nparray[rh] IndexError: index 0 is out of bounds for axis 0 with size 0

Proposed changes

• indication.py

Test

Code:

Result: