如何在特定时间点控制self.play运行

How to control self.play run at specific time point

假设有两个 self.play 语句,第一个从 1s 开始,我想秒数从一开始正好从 3s 开始。

目前我使用self.wait来控制步骤:

self.wait(1)
self.play...... # first animation
self.wait(2)    # because 1 + 2 = 3
self.play...... # second animation

然而,由于第一个动画需要一些时间(例如 1.5s)才能完成,实际上第二个动画将在 1 + 1.5 + 2 = 4.5s 开始。

如何让第二个 self.play 从开始 运行 开始正好 3 秒? 提前致谢。

你是说这个吗?

class SuccessionExample(Scene):
    def construct(self):
        number_line=NumberLine(x_min=-2,x_max=2)
        triangle=RegularPolygon(3,start_angle=-PI/2)\
                   .scale(0.2)\
                   .next_to(number_line.get_left(),UP,buff=SMALL_BUFF)
        text_1=TextMobject("1")\
               .next_to(number_line.get_tick(-1),DOWN)
        text_2=TextMobject("2")\
               .next_to(number_line.get_tick(0),DOWN)
        text_3=TextMobject("3")\
               .next_to(number_line.get_tick(1),DOWN)
        text_4=TextMobject("4")\
               .next_to(number_line.get_tick(2),DOWN)

        self.add(number_line)
        self.play(ShowCreation(triangle))
        self.wait(0.3)

        self.play(
                    #The move of the triangle starts
                    ApplyMethod(triangle.shift,RIGHT*4,rate_func=linear,run_time=4),

                    AnimationGroup(
                        Animation(Mobject(),run_time=1),#<- one second pause
                        Write(text_1),lag_ratio=1       #<- then start Write animation
                    ),
                    AnimationGroup(
                        Animation(Mobject(),run_time=2),#<- two seconds pause
                        Write(text_2),lag_ratio=1       #<- then start Write animation
                    ),
                    AnimationGroup(
                        Animation(Mobject(),run_time=3),#<- three seconds pause
                        Write(text_3),lag_ratio=1       #<- then start Write animation
                    ),
                    AnimationGroup(
                        Animation(Mobject(),run_time=4),#<- four seconds pause
                        Write(text_4),lag_ratio=1       #<- then start Write animation
                    ),
            )

        self.wait()