Add set_anim_args to .animate method

[widcardw]

Motivation

With the pr of manim community, we can easily use .animate method to build Animation, but we cannot change the arguments of Animations. With the set_anim_args method, we can change args of Animation. Since _AnimationBuilder will build it into MoveToTarget, we can also use path_arc or path_func and so on.

Test

class TestAnimateArgs(Scene):
    def construct(self) -> None:
        a = Circle().to_edge(LEFT)
        anim_builder = (
            a
            .animate
            .scale(3)
            .to_edge(RIGHT)
            .set_anim_args(run_time=3, time_span=(1, 2), rate_func=double_smooth, path_arc=PI/2)
        )
        self.play(anim_builder)

TestAnimateArgs.mp4

[widcardw]

Now you can also pass args by calling the animate method, which is borrowed from manim community. The method set_anim_args also works.

class TestAnimateArgs(Scene):
    def construct(self) -> None:
        a = Circle().to_edge(LEFT)
        anim_builder = (
            a
            .animate(run_time=3, time_span=(1, 2), rate_func=double_smooth, path_arc=PI/2)
            .scale(3)
            .to_edge(RIGHT)
        )
        self.play(anim_builder)

Or

class TestAnimateArgs(Scene):
    def construct(self) -> None:
        a = Circle().to_edge(LEFT)
        anim_builder = (
            a
            .animate
            .scale(3)
            .to_edge(RIGHT)
            .set_anim_args(run_time=3, time_span=(1, 2), rate_func=double_smooth, path_arc=PI/2)
        )
        self.play(anim_builder)

BTW, the Animation args can only be passed ONCE. You should AVOID using it like below

        anim_builder = (
            a
            .animate(run_time=3, time_span=(1, 2), rate_func=double_smooth, path_arc=PI/2)
            .scale(3)
            .set_anim_args(run_time=5)  # !!! the second time that pass the args may raise error
        )

[3b1b]

Thanks!