manimの作法 その60

概要

manimの作法、調べてみた。
add_updater、使ってみた。

サンプルコード

from manimlib.imports import *

def temperature_to_color(temp, min_temp = -1, max_temp = 1):
    colors = [BLUE, TEAL, GREEN, YELLOW, "#ff0000"]
    alpha = inverse_interpolate(min_temp, max_temp, temp)
    index, sub_alpha = integer_interpolate(0, len(colors) - 1, alpha)
    return interpolate_color(colors[index], colors[index + 1], sub_alpha)

def two_d_temp_func(x, y, t):
    return np.sum([c * np.sin(f * var) * np.exp(-(f ** 2) * t) for c, f, var in [(0.2, 1, x), (0.3, 3, x), (0.02, 5, x), (0.01, 7, x), (0.5, 2, y), (0.1, 10, y), (0.01, 20, y), ]])

class test(ThreeDScene):
    CONFIG = {
        "cells_per_side": 20,
        "body_height": 6,
    }
    def construct(self):
        self.introduce_body()
        self.show_temperature_at_all_points()
    def introduce_body(self):
        height = self.body_height
        buff = 0.025
        rows = VGroup(*[VGroup(*[Dot(stroke_width = 0, fill_opacity = 1, ) for x in range(self.cells_per_side)]).arrange(RIGHT, buff = buff) for y in range(self.cells_per_side)]).arrange(DOWN, buff=buff)
        for row in rows[1::2]:
            row.submobjects.reverse()
        body = self.body = VGroup(*it.chain(*rows))
        body.set_height(height)
        body.center()
        body.to_edge(LEFT)
        axes = self.axes = Axes(x_min = -5, x_max = 5, y_min = -5, y_max = 5, )
        axes.match_height(body)
        axes.move_to(body)
        for cell in body:
            self.color_cell(cell)
        plate = Square(stroke_width = 0, fill_color = DARK_GREY, sheen_direction = UL, sheen_factor = 1, fill_opacity = 1, )
        plate.replace(body)
        plate_words = TextMobject("Piece of \\\\ metal")
        plate_words.scale(2)
        plate_words.set_stroke(BLACK, 2, background = True)
        plate_words.set_color(BLACK)
        plate_words.move_to(plate)
        self.play(DrawBorderThenFill(plate), Write(plate_words, run_time = 2, rate_func = squish_rate_func(smooth, 0.5, 1)))
        self.wait()
        self.remove(plate_words)
    def show_temperature_at_all_points(self):
        body = self.body
        start_corner = body[0].get_center()
        dot = Dot(radius = 0.01, color = WHITE)
        dot.move_to(start_corner)
        get_point = dot.get_center
        lhs = TexMobject("T = ")
        lhs.next_to(body, RIGHT, LARGE_BUFF)
        decimal = DecimalNumber(num_decimal_places = 1, unit = "^\\circ")
        decimal.next_to(lhs, RIGHT, MED_SMALL_BUFF, DOWN)
        decimal.add_updater(lambda d: d.set_value(40 + 50 * self.point_to_temp(get_point())))
        arrow = Arrow(color = YELLOW)
        arrow.set_stroke(BLACK, 8, background = True)
        arrow.tip.set_stroke(BLACK, 2, background = True)
        arrow.add_updater(lambda a: a.put_start_and_end_on(lhs.get_left() + MED_SMALL_BUFF * LEFT, get_point(), ))
        dot.add_updater(lambda p: p.move_to(body[-1] if (1 < len(body)) else start_corner))
        self.add(body, dot, lhs, decimal, arrow)
        self.play(ShowIncreasingSubsets(body, run_time = 10, rate_func = linear, ))
        self.wait()
        self.remove(dot)
        self.play(FadeOut(arrow), FadeOut(lhs), FadeOut(decimal), )
    def point_to_temp(self, point, time = 0):
        x, y = self.axes.point_to_coords(point)
        return two_d_temp_func(0.3 * x, 0.3 * y, t = time)
    def color_cell(self, cell, vect = RIGHT):
        p0 = cell.get_corner(-vect)
        p1 = cell.get_corner(vect)
        colors = []
        for point in p0, p1:
            temp = self.point_to_temp(point)
            color = temperature_to_color(temp)
            colors.append(color)
        cell.set_color(color = colors)
        cell.set_sheen_direction(vect)
        return cell

生成した動画

以上。