py

from manim import *

class BigStealthTip(ArrowTip):
    def __init__(
        self,
        fill_opacity: float = 1,
        stroke_width: float = 3,
        length: float = DEFAULT_ARROW_TIP_LENGTH / 2,
        start_angle: float = PI,
        **kwargs,
    ):
        self.start_angle = start_angle
        VMobject.__init__(
            self, fill_opacity=fill_opacity, stroke_width=stroke_width, **kwargs
        )
        self.set_points_as_corners(
            np.array(
                [
                    [2, 0, 0],  # tip
                    [-1.2, 7.6, 0], # modified
                    [0, 0, 0],  # base
                    [-1.2, -7.6, 0], # modified
                    [2, 0, 0],  # close path, back to tip
                ]
            )
        )
        self.scale(length / self.length)

    @property
    def length(self) -> float:
        """The length of the arrow tip.

        In this case, the length is computed as the height of
        the triangle encompassing the stealth tip (otherwise,
        the tip is scaled too large).
        """
        return float(np.linalg.norm(self.vector) * 1.6)

class HalfStealthTip(ArrowTip):
    def __init__(
        self,
        fill_opacity: float = 1,
        stroke_width: float = 3,
        length: float = DEFAULT_ARROW_TIP_LENGTH / 2,
        start_angle: float = PI,
        **kwargs,
    ):
        self.start_angle = start_angle
        VMobject.__init__(
            self, fill_opacity=fill_opacity, stroke_width=stroke_width, **kwargs
        )
        self.set_points_as_corners(
            np.array(
                [
                    [2, 0, 0],  # tip
                    [-1.2, 1.6, 0],
                    [0, 0, 0],  # base
                    [-1.2, -7.6, 0], # modified
                    [2, 0, 0],  # close path, back to tip
                ]
            )
        )
        self.scale(length / self.length)

    @property
    def length(self) -> float:
        """The length of the arrow tip.

        In this case, the length is computed as the height of
        the triangle encompassing the stealth tip (otherwise,
        the tip is scaled too large).
        """
        return float(np.linalg.norm(self.vector) * 1.6)

class TipTest(Scene):
    def construct(self):
        fineArrowWithBigTip = Arrow(start=RIGHT, end=LEFT, tip_shape=BigStealthTip)
        badArrowWithAsymmetricTip = Arrow(start=RIGHT, end=LEFT, tip_shape=HalfStealthTip)
        badArrowWithAsymmetricTip.next_to(fineArrowWithBigTip, DOWN)
        self.play(
            Create(fineArrowWithBigTip),
            Create(badArrowWithAsymmetricTip),
        )
        self.wait()